HOW TO: Keep Your Car Stereo On While Starting

I don't like to idle for long, but I hate interrupting music to restart the car. Here's a hack that prevents your stereo from turning off when cranking to (re)start the engine. Should work on most aftermarket stereos.
YMMV, as different stereos may draw more current through their accessory turn on wire.
Music: / amboise

[@StephenTack]

Here are are good starting points for capacitor and diode on Amazon: Nichicon UVZ1C222MHD-20 Aluminum Electrolytic Capacitors - Leaded 16V, 2200uF, 12.5 mm x 20 mm, 20% Tolerance, 5LS (Pack of 20) www.amazon.com/dp/B071RTXD64 Cafurty 1N4007 DO-41 Axial Silastic Guard Junction Standard Rectifier Diode (Pack of 20) www.amazon.com/dp/B00W17LOBO If you're having trouble with the stereo resetting when you crank the engine, but when the ignition is turned off the stereo stays on for a few seconds, the starter is causing the voltage to the stereo to sag. Things to check: corrosion on the battery terminals, old/week battery, bad connections in any wires. If these are not the case, you can try adding a capacitor to the yellow power wire as well. Here is a video on that mod: kzbin.info/www/bejne/aJyWe2ykd955h6M

[@DSJVNdsjnvf4356]

thanks for this, I was really desperate to know the exact pieces lol

[@StephenTack]

@@DSJVNdsjnvf4356 the secret is, this will work with a huge variety of different capacitors and diodes. There are likely usable components to be salvaged in most dead electronics. 🤗

[@DSJVNdsjnvf4356]

@@StephenTack hey man, idk what happened but I’m pretty sure I got shocked..can you help me out by what went wrong? It felt like a hot wire went up my arm.. Btw my acc fuse blew at that same time…sorry man Idk anything about this stuff

[@StephenTack]

@@DSJVNdsjnvf4356 sounds like you should be looking for some in-person help... Make sure no electrical connections are touching, and they are all taped or heat shrinked well.

[@DSJVNdsjnvf4356]

I mean it works! Believe me! Now I can turn my car off if I’m idling for too long and then start my car without my Bluetooth going off! It’s so much easier now! The only issue is I don’t know how I got shocked during the installation process. I mean a 16 v capacitor shouldn’t shock you or have that much current go through you since the human body has a large resistance…but unfortunately I did get shocked. Tbh it was a shock, it fell like a current just going through my body! Idk, the whole thing works and all, but I just don’t want to get electrocuted again. I taped everything up, believe me, and I even used old telephone wire and hot glue to keep everything from shorting out. Hard to say what exactly happened..

[@DSJVNdsjnvf4356]

Update: it’s been about 10 months since I put this in my car. Not only am I able to keep Bluetooth connected while I feel my gas tank, I have probably saved over gallon of gas by not idling, and just simply enjoying my stereo bass lmao. This video cannot thank enough. It was a pain though to install the capacitor and wiring though but it has paid off..

[@DavetheRaveDinkum]

Awesome

[@brapamaldi7666]

dude, 4 years down the track and your awesome little video is still helping people out. thanks a bunch man, this fixes one of the major annoyances I have with my car. had a feeling a capacitor was what i needed, but had no idea something so small would do the trick. sweet!!!! cheers again man, you're the MVP!

[@souls_gt7120]

Firstly I like to say Thank you Stephen for this short video mate, this has helped many people including me, after long research your short video solve my problem I’m very happy I’ve installed 2x 2200fu capacitor in parallel 1X Diodes, installed incorrectly and it’s working. Thank you once again mate 🙏🏼

[@rannz7]

You've helped me out sooooooo much!!! I was really annoyed that my stereo just shuts off when starting the car. I deliver food for a living and gotta keep starting and shutting off my truck and the like to listen to music while I wait, pickup, and drop off food.

[@wakenup23v]

Thanks!!!! I can still learn something new everyday. This worked amazingly for an Android car stereo on a older kit car with some suspect wiring. I had to use it on the hot lead because when the engine was turning over, it pulled enough battery to cause the stereo to lose enough power reboot very time you started the car. The capacitor solved the issue. BTW, I did confirm the battery was in good shape. Many thanks.

[@brendanoshea4128]

GOOD MAN! Great instructions. Yep, it sucks when starting the car drops your bluetooth phone link, you solved my problem! Thanks for taking the time to post this :)

[@StephenTack]

Happy to be of service. :-)

[@Loyal_Honda_Fan]

Dood your video saved me a bunch of money, i made an explanation to other videos and sites on how to fix the problem on the same car as i have and shared your video, you actually fixed my navigation system ^^ Thanks again buddy!

[@StephenTack]

+Loyal Honda Fan Rad! Glad it was helpful! #subaru

[@hugozuniga3707]

we're you get the parts

[@StephenTack]

Old power supplies... Or eBay/Amazon

[@BAQ1912]

I was having this issue on my boat and a capacitor alone didn't work. When starting the boat, the power appeared to be cut off through the factory wiring, likely to give the starter as much current as possible. My method required a capacitor and a relay. I put the cap (10k uF 35v I had laying around, probably overkill) on the original power source, similar to the video shows, but then wired that to #86 on a relay. I then ran a direct 12v source to the relay (#30 in, #87 out, #85 to ground). The capacitor proved to be enough to keep the relay open while starting my boat, providing a solid 12v signal the whole time.

[@toniflash8491]

thank you very much for your post. I guess you are going to save my life. I recently bought one of those chinese head units for my twenty year old car. Thanks to this stereo, I feel just like driving a brand new car, but that annoying hasle of restarting android during ignition is making me have nightmares. It is not just the music but also the navigator. If I have to stop the car to pump some gas, I have to start the stereo again and let´s not forget it really takes a time to run properly(the processor in these devices is usually very weak). I haven´t tried it yet, but I hope everything is going to be fine. Aside from that, some more advice is always welcome.

[@87Runner]

Perfect, just what I was looking for!

[@mr.bitsbyte4664]

Thank you! I have the same issue in my car. I thought about adding a capacitor to fix it but I wasn't sure it would work. I'll have to give this a try.

[@andytimmons1950]

Perfect, just what I was looking for! thank you so much

[@Clougherty]

Nice little video that stand the test of time. Sony XAV-AX100 with 16V 2200uF and 1N4001 Diode allow me to park turn off the key and then restart the car without restarting the stereo in a VW Jetta. When i take the key out its just a few seconds extra before the stereo turns off. Its a hack but solves the problem of not having the reboot when i restart the car picking up the kids. Cheers

[@bwesley3034]

Thank you for sharing this information. Thank you for actually applying some basic editing in doing so. I found your video in the middle of *hundreds* of capacitor-for-car-audio videos, virtually all of them describing how to to create a wall *against* how much power is fed into someone's amplifier. I didn't need that. I needed EXACTLY what you described, and was able to source the 16v cap's I needed. Look forward to wiring this up soon, with the help you personally provided. It's a tragedy this video doesn't have a couple thousand more views. As I'm in the process of learning Manual, I stall plenty, and look forward to *not* losing 10 seconds (new pioneer NEX boot sequence) plus another 10 seconds (handshake with USB phone device providing navigation) every time I sneeze and have to restart the ride! :-)

[@StephenTack]

Thanks for the kind words. I'm glad this is helping people. Congratulations on learning manual, it opens up a whole new world of motoring! 🌐🚗

[@chloeleedow7250]

Every time you sneeze 🤧😂 I stall my manual too bud been driving for 3 years but it's a new car for me so stall it a lot I do on and a bung o2 sensor is giving me crappy idle I think. Great video thanks Stephan mate 😊

[@indonet545]

Amazing dude.. Your video make me happy everytime i see video on my car headunit now because i solve my problem.. Thanks so much. 🙏

[@infopinoynz]

Thanks, man it's helpful information on how to add a capacitor and diode to my car stereo

[@guitarguy3221]

How did you connect the tiny electronic leads to 18awg car wire?? I'm using that capacitor with alligator clips and reading immediate voltage drop to 3V when cranking

[@markanderson1519]

Outstanding. Exactly what I needed.

[@alexandrudumitrache2594]

I have an older car to which I have added a Bluetooth receiver, powered from a 12v socket. Can I add something like this to that socket? It doesn't need big power and that socket only powers that particular device, but I lose Bluetooth connection every time I start the car...

[@Purple_Zergling]

Worked like a charm Thanks!

[@roebuck2049]

Hi tried same resistor but fails to keep my Jvc double din stereo on when I turn ignition off. Any advice , do I need to up the size ? Only thing is I haven't put a diode inline ,would this be it ? Am I loosing the charge back down the line to say the ignition barrel etc.

[@StephenTack]

Hmm.. By "resistor" do you mean capacitor? ...that would be the problem if not. And yes, depending on what else is connected to your accessory switch, the diode is essential to keep the capacitor's charge from bleeding out.

[@ivankovacevic5348]

Works Like a charm! Thanks

[@souls_gt7120]

Hi another question if you don’t mind. If I want to add 2x capacitor 16v 2200fu & 2x Diode? Will be any problem?

[@StephenTack]

You can add a second capacitor in parallel, but you should only need one diode.

[@yarsftks]

Nice. How did you determine the size of the capacitor? And would you know how to make a similar connection so that it stays on until you open the door? thanks, frank s.

[@StephenTack]

It all depends on how much current the red wire of your stereo draws. I just salvaged a 2200uF capacitor, tried it, and it was the right size for my stereo. You could hook an meter up in line with the red wire, in "amps" mode to find the draw, then plug that in to this equation: TimeYouWantItToStayOn ÷ (Voltage ÷ Current) = Capacitance in Farads In my case this was about: 4S ÷ (13V ÷ 0.0072A) = 0.0022F = 2200uF To get it to stay on until you open the door, you'd probably have to use a relay or two... Could be done, but it's a totally different circuit.

[@CARBONJUNIORS]

Hi i have a sony XAV-3005DAB radio with apple carplay which charges the phone at the same time and also has a screen so im assuming it will use quite a lot more power. Do you think it will still keep my stereo on while cranking?

[@StephenTack]

That really depends on the health of your battery, and the battery connections. This mod only needs to supply a turn on signal, it doesn't really supply power. It's worth a try.

[@teemum.9023]

Does this work when I shut down ignition by turning the key off for a moment or does it work only when the power is on and cranking?

[@StephenTack]

Both.

[@JoseMaria-de3un]

I have a 63v dc capacitor with 6800uf and a 250v dc with 2200uf. I know is to high in voltage but someone commented for a 25v that was 10v safe. can I use it or will be a nice bang and my car will burn?

[@StephenTack]

Any cap rated for 16v or more is safe. The higher voltage ones will just be physically much larger.

[@joetaylor010]

Works great - thanks!

[@donwolfjr1]

Does anybody know what diode to use or if it's even necessary?? Thanks!!

[@pranjalsaxena1678]

Any diode would work. Because is just a few mili amps. 1N4007 will be good though.

[@kilerek3]

i have question which can't find answer anywhere. How long 2200uf capacitor can power up radio?

[@StephenTack]

It really depends on the radio, some draw more than others on their turn on wire. Some experimentation may be required.

[@PhoebeEtc]

I'm overdue for a new battery so I won't try this straight away, but do you happen to remember which diode you used? I have a heap of junk power supplies to cannibalise parts from, but your diode looks brand new part. Did you just look up "14v diode" on a parts website or do I need to know more than that?

[@StephenTack]

That's just a stock picture. I pulled mine from an old power supply. Basically any diode that looks beefy and black will work for this.

[@PhoebeEtc]

@@StephenTack dope. Makes sense, just a big fat DC one way gate.

[@user-fk7on9zj4i]

Hello Car is Subaro media is pioneer avh x8600bt I tied it up according to the scheme but still restart give a suggestion how to handle it

[@StephenTack]

Have a read through the other comments, we've covered a lot of possible solutions. Cheers!

[@mrdg123]

So I have just sired this in exactly as you described. But it doesn't work. The radio comes on as normal but turns off when cranking.... it a new radio, an eonon. Any suggestions? I was so chuffed with my work, such a pity it doesn't work in my radio.

[@StephenTack]

How long does it stay on after you shut the ignition off? It may be that your starter is making all of the voltage sag too low. Have a look at the other comments here for ideas. Cheers.

[@shubhamvc4524]

it worked for me and is it ok to use a 2200,25v capacitor

[@StephenTack]

Glad it worked for you! Yes the voltage rating of the capacitor just needs to be more than the voltage with which you are working, plus a bit for safely. In this case a car's charging system gets up to around 14.5V, so your 25V cap gives you a 10.5V safety margin.

[@Ben79k]

thanks for this video. Wasnt too sure if this would work/was possible. I hate having all those nice salvaged caps around and feeling like i shoudnt use them, all the main sources online say to use one of those stupid pre-built car audio capacitors which are WAY over priced. going to give it a shot when ever I find a diode to use.

[@donwolfjr1]

Hey Ben, I know its been three years ago but...do you remember what diode to use in this case?!? Thanks!! Don

[@StephenTack]

Basically any round, black diode will work.

[@ebyoommen1]

Hi Stephen..what if we short the accessory wire to the 12V battery + wire...in this case the power to the stereo unit should never get OFF. And switching ON/OFF can be done through the front switch of the stereo unit. Is it a viable and safe option ? Just curious ..

[@StephenTack]

Yeah, you could just hook both red and yellow wires in the stereo to the always on wire... But the chance of leaving the stereo on, and running down the battery would increase. And I like the stereo to turn on automatically when I start the car.

[@StephenTack]

Just don't short the car's accessory wire to the battery wire.

[@ebyoommen1]

@@StephenTack OK..I got that..No shorting ..Thanks

[@ebyoommen1]

Hi Stephen.. Is it safe to add a similar circuit for the mains +12V ? During cranking , 12v drops to almost 8.5V and the stereo trips even after adding this circuit on the accessory wire. I have read that you added 47000 microfarad capacitor on the mains +12V and it worked. Are there any precautions to take, if I try this ? What would be the rating of the diode in such a case ?

[@StephenTack]

@@ebyoommen1 Any large diode should work, if you have a multimeter with a diode check mode, try to select a diode that has the smallest voltage drop, as this will reduce the operating voltage the least. Just be sure that all the connections are insulated (tape and/or heat-shrink tube), so they won't short out to exposed metal inside the dash. Other things to check if the battery voltage is sagging a lot while cranking, is the health of the battery (old batteries sag more), and for good corrosion-free connections to the battery and the ground-wire to the frame and engine. Any point of resistance in this main circuit will cause a large voltage drop while the starter is drawing a lot of currant. Good luck!

[@ting2222]

I have the same problem. Radio reboot when starting the engine. I tried this. Did not work. Found out, radio reboot because of the drop in voltage from constant battery line, not the shut off of accessory power. Problem till exist on mine. Exploring other options, bigger battery, add second battery, add capacitor?

[@StephenTack]

Read through the comments, there and been multiple other people with that problem.

[@yota5692]

I tried this yesterday on my Atoto A6. Happens that when i turn ignition on, battery voltage drops to 5 or 6v, so i had to do the mod on the batterys cables, black and yellow. It's working better now, but not enough to prevent the radio to turn off a little bit. Thanks for the video ☺️

[@goncalocardoso5437]

What type of diode should I use?

[@StephenTack]

gonçalo Cardoso pretty much any common diode will work. good sources are old power supplies, and DC "wall warts" you have languishing in a drawer. Note: different stereos may have different amounts of draw on the turn on wire, so you may need to experiment with different values of capacitors. Hope this works for you as well as it did for me.

[@IbRidO]

Thanks works great, with a 2200 24v capacitor my cheap android unit stays on for more than 2 minutes after removing key.

[@StephenTack]

Nice. It seems modern, cheep stereos have very sensitive turn-on circuitry. I recently had a cheep Boss that would stay on virtually forever... If you want it to be shorter, a resistor can be added across the capacitor to drain it and shut the stereo off sooner. I guess appropriate sizes would be 100k to 1M ohm. 🤷🏻

[@mobinbalkhi8521]

Can anyone tell how to fins acc wire on car stereo ? There is 2 wire with 12volt, one wire which while ignition drops voltage to 10 and another wire which while ignition cuts the power completely, so i was wondering which wire should i install capacitor to? Thanks

[@StephenTack]

The one that turns off. And don't forget the diode.

[@teemum.9023]

are the two fuses inside or in engine fuse box?

[@StephenTack]

Depends on the car.

[@mihailpetrovici5044]

I connected the red wire to the yellow as well, so it's on all the time, the yellow wite doesn't get voltage drop while cranking so the red one should get the 12v as well but the radio still turns off. Can the radio itself have some king of feature when the voltage drops to 10v while cranking it turns off by itself?

[@StephenTack]

Not a feature, it just can't run on the low voltage that happens when cranking. Check your battery connections, check the health of your battery.

[@mihailpetrovici5044]

@@StephenTack the battery seems healty, I check with a multi meter the to see which wires have current when and I saw the voltage drop to 10v at max, is that low for cranking?

[@PhoebeEtc]

Also it might sound ridiculous but for people who're trying this and it isn't working, see how it goes with your stereo not playing music. There's voltage sag during cranking because the starter pulls so many amps from the battery, could be that your stereo stays on but if your stereo is pulling serious load (like playing music through a decent or even stock) system then it might not cope with the sag. If you can keep the stereo from restarting then you probably just need a battery rated for higher cranking amps and it'll work for you too.

[@HeroClaws]

I had that problem, i added big power bank to the main pwr wire (yellow), i have video on my channel describing if this video does not help, and stereo keeps shutting down due to voltage sag. I've put 2 big 16V 47000uF caps, ~ 0.1F as a " power bank " to the yellow wire with the diode. Installed it probably 7 8 months ago, no problems at all. Did not change the battery (although it is now roughly 2.5 years old). You can check it out.

[@singgiha]

As far as i know, the HU reboot is not triggered by the absence of the ACC signal, instead because the main DC power mostly withdrawed to crank up the engine. Yes, i know may be this must depends on each HU design that differ from one to another. And in your case, could be saved by the internal HU power supply which might have more backup power capacitor inside. Just my 2cents.

[@StephenTack]

Yes. Voltage sag on the always on yellow "bat" wire while cranking the starter can cause the HU to reboot. But I've added this diode-capacitor ACC red wire circuit to many vehicles now, with many different head units, and it works in most cases. At the least, it is required if you want to keep the HU on while cranking, because in every case the ACC voltage is totally shut off while cranking. With a healthy battery, and good connections, in not freezing weather the lowest voltage sag I've measured on the yellow wire is about 10v... Most head units won't reboot till about 8v, though their amplifies may momentarily brown-out a bit sooner. The solution i have used for this problem is either a fresh battery, removing corrosion from the battery terminals, or adding a very large capacitor and diode to the yellow wire (which can help with the stereo hit harder anyway}. Cheers!

[@singgiha]

@@StephenTack well.... that is a lot of new informations for me.... thanks for sharing.... really appreciate it.... i'll try it my self, because i really need my headunit stay on while starting the engine.....

[@rikki146]

​@@StephenTack EDIT: Stupid me. Allow me to change my question: which capacitor and diode do you recommend for a head unit with 9inch LCD screen? Cheers

[@SerenoOunce]

Only change I would make is to add a 1K resistor inline w/ the diode. This is to protect the both the diode and cap from the initial surge current as it charges. As for the capacitor, typically a 1000uf is sufficient for ~ 5-8 sec though I would go with a 25V over 16V if possible for longevity. A cap's V rating is it's max voltage, not necessarily it's working V, so having < 30% headroom is recommended.

[@StephenTack]

The inrush resistor is a good idea, but I find it adds an annoying delay to the turn on. I've mostly used WAY overspec'd diodes for the job, and only had one die when I tried a little signal diode (with a lower forward voltage drop). As for capacitor size for a particular stay-on time, it depends on the stereo. I'll post a way to guesstimate the internal resistance (current draw) on the red wire. 25V would be a better safety margin, but the cap is significantly larger, and again I've never had one die. 🤷🏼‍♂️

[@StephenTack]

To size the cap: "You could hook an meter up in line with the red wire, in "amps" mode to find the draw, then plug that in to this equation: TimeYouWantItToStayOn ÷ (Voltage ÷ Current) = Capacitance in Farads In my case this was about: 4S ÷ (13V ÷ 0.0072A) = 0.0022F = 2200uF

[@SerenoOunce]

@@StephenTack If using a 1K R with a 2200uf cap I can see there being a possible extra ~2 sec delay. IMO a 2200uf is a bit overkill. I've used a 1000uf in multiple systems and any delay has been negligible. Component parts will be cheaper as well as you only need them spec'd for 200mA. But also comes down to what you have on hand.

[@Mikkel111]

I just purchased a 25V 10000 uF to use for this purpose. Does it still have a measurable delay when not using a resistor?

[@Mikkel111]

I went for 10000 as I was hoping it would stay on while music was playing.

[@traxxx8720]

Thank you man for this video ! Can't believe how long the capacitor can feed my stereo after cutting off power. I placed a 2200uF 16V capacitor and my unit runs for about 30 seconds after ignition removal. Far more than what I expected ! Do you just have an idea of how long I can expect the capacitor to last before it blows or something ? (In a normal use)

[@StephenTack]

Congrats on getting it working well! In the configuration I show here the capacitor is not feeding the stereo "power," just keeping the stay on signal voltage high. Power is drawn directly from the battery, through the yellow wire. If 30 seconds is longer than you want the stereo to say on, you can decrease the capacitance, or add a high value resistor in parallel with the capacitor (I'd t try 100K ohm to start). In this roll the capacitor isn't being strained too much, it should last for a long time. The only thing you could do to make life easier on it would be reduced the in-rush when you turn the ignition on, by putting a low value resistor 10-100 ohm between the diode and the capacitor.

[@traxxx8720]

Stephen Tack I'm not much of an expert in electric and electronic stuff. I've made exactly the same wiring as yours. Tell me if I'm wrong but the capacitor is just feeding the stereo with electricity when there is a current cut when turning on the engine and also after shutting off power, the residual energy is making it on for a certain time before it shuts down. Can you explain to me in an easier way what you suggested ? What is the role of the resistor in your suggestion ? Is it decreasing voltage, intensity for the capacitor ? And how do you determine the ohms value ?

[@aalani]

@@traxxx8720 Can’t see a resistor in Stephen’s diagram! 🤔

[@dhira88]

Hi i have hyundai i 10 car with single din sony stereo . I have tried with 3300 mf 25v capacitor with 1n4007 diode in red wire . Still stereo is switching off immediately after power off and switching on late after ignition . Please give some suggestion

[@StephenTack]

That's very interesting! 🤔 I'll be thinking about what could cause that behavior. The only things I can suggest are checking the diode, and making sure that the capacitor is connected to the red wire and the ground wire (not in line with the red wire). Hope you get it working. If so, do tell what it was. Cheers!

[@dhira88]

Hi ...diode is correctly fixed and capacitor positive leg is connected with red wire and negative leg with black ground wire . Only thing is the wire connecting diode and capacitor used is very thin aluminium wire used for dvd tapes. Can that be the reason

[@StephenTack]

@@dhira88 😮DVD TAPES!? If that wire is really thin, maybe. You can just connect the stripe side of the diode directly to the positive side of the capacitor AND the red wire going to the stereo.

[@technovariable831]

Thank you so much Stephen, this worked. My setup is with 1000 microfarad 25V capacitor and it hold for 35 seconds, once I take out the car keys! Do I need to put a resistor somewhere to increase the life of capacitor?

[@StephenTack]

Wow, good result, your stereo must have very little draw on the red wire. None of the capacitors I've used have been damaged yet, with just the diode to block back-flow... I have have a diode fail when I used a fancy low-forward-voltage drop one instead of just a beefy power diode harvested from an old power supply. Cheers!

[@technovariable831]

@@StephenTack Cheers! Now trying this setup on my other car. I bit customized this one, put a connecter in between where I can change the capacitor without resoldering. In case you need to see, mail me Hi at [e-mail]

[@technovariable831]

@@StephenTack Completed this in my other car, and it worked again. Here 1000 microfarad capacitor helps during start, but JVC 220 BT seems to consume more power, after key off the stereo goes off in 2.5 seconds.

[@StephenTack]

@@technovariable831 that's aligns with my experiences. I've been using 2200-3600 and getting 5-10 seconds.

[@technovariable831]

@@StephenTack Thank you so much for sharing your valuable experience.

[@usaryder74]

cool. I am so doing it on mine. Thanks

[@russellb1981]

This didn’t work for me. I even added 4 capacitors to see if the system needed more power. But the stereo always shuts off briefly on start up. The multi meter shows a drop from 12v to around 9v on the constant live and ignition live wires on start up. When I turn the engine off the capacitors last around 9/10 seconds before they drop down from 11.85v to 8.5v which is then too low to power the stereo and it shuts off. Any suggestions?

[@StephenTack]

Yep, the starter is pulling the voltage below the stereo's amp's low voltage shutdown. If you can find some very large capacitor, like at least a couple 50,000uFd 16V capacitors in parallel, and a beefy rectifier diode, you can do the same thing to the constant power wire. Or... Get a fresher/bigger battery, and make sure there is no corrosion on the terminals. Ciao!

[@russellb1981]

Stephen Tack Not even sure where I’d find a 50,000uFd capacitor. How long would a cap this size keep the stereo running for after shut down? Would a couple of 10,000-25v caps be any good??

[@StephenTack]

@@russellb1981 might help, keep adding them in parallel if it doesn't work... But your best bet is to be sure that your battery is well connected and fresh first, if it doesn't sag as much while cranking, the capacitors on the constant may not be needed.

[@StephenTack]

So, capacitors on the yellow wire (12V constant) only need to supplement the battery voltage while it's sagging during engine crank. How large they need to be to prevent your stereo from shutting down depends on a lot of things: 1, how long your starter needs to be cranked to start your vehicle. 2, the health of your battery and its connections. 3, how much power your stereo is drawing...if you are playing music very loud while cranking, or if your stereo is old and inefficient, you'll need bigger capacitors. I got a couple 47,000uF from "Surplus Gizmos" for cheap, in parallel, and with a diode upstream they keep my Pioneer stereo on while cranking.

[@rhunt2363]

@@StephenTack What parameters make for a "beefy" rectifier diode? What specs should i be looking for?

[@trulyblockchain]

will this trick work with Blaupunkt SL350..?

[@StephenTack]

Probably. Give it a try.

[@zanderlukas1248]

Hi there thanks for this video, I ran into some problems with my canbus headunit installed it at a garage sometime back and when you turn on the car by right the headunit should do so however even pressing the power button doesn't do it either only when I press the tiny reset button only then it powers on. Strange part is when you turn off the car and turn it on again it works however if you leave the car say turn off for an hour and then turn it on again it doesn't work and you're back to using the reset button again. Thanks in advance

[@StephenTack]

Too many variables to know what's wrong. But I'd guess either the wiring is wrong, or the head unit is defective. 🤷‍♂️ I'd start troubleshooting by googling it in a variety of ways....

[@XxSCaaRyFiEnDxX]

Hey man, Awesome video I'm looking at wiring this into my stereo as well so it doesn't lose connection to the bluetooth but I was wondering if there's a way to wire the stereo in so that it turns off when the ignition is turned off after the car has been running but is able to be turned back on when the ignition is completely off? So the passenger is able to turn it on without a key in the ignition. I've been searching for solutions and have found people wire it to a constant 12v power when the ignition is off, but I believe this essentially means it's powered on all the time. So that solution doesn't seem to be the same as the OEM setups in come cars. Would there be a solution to this? Thanks.

[@StephenTack]

If you have a place to mount a small toggle switch, you could have it select if the stereo's red wire connects to the normal on-with-ignition (red) wire, or to the always-on (yellow) wire.

[@XxSCaaRyFiEnDxX]

@@StephenTack Thanks for the reply! Yeah I saw those as well but I'm going for a stock look, in your opinion would this be possible without a toggle switch?

[@XxSCaaRyFiEnDxX]

@@StephenTack Is this capacitor a good one to get? or should I get a non-low ESR one? www.jaycar.com.au/2200uf-16vdc-low-esr-electrolytic-capacitor/p/RE6318

[@StephenTack]

@@XxSCaaRyFiEnDxX what you want to do would only be possible with and advanced circuit or microcontroller...or toggle switch. That capacitor looks fine. You don't need low ESR. But I'd recommend getting at least 2 2200uf caps. If 1 isn't enough you can add a second one in parallel.

[@XxSCaaRyFiEnDxX]

@@StephenTack Sweet thanks, I'll look into it.

[@gabo42013]

great video! I followed all of the steps however the radio still shuts off when cranking. I have a custom android radio so I would assume it takes more power to keep it on. assuming this, I purchased a 4700, 35V capacitor. I tested the voltage drop on my accessory wire and it dropped to -0.02VDC. after I connected the capacitor with diode, it drops to ~+3.7VDC. do I need for capacitors or am I doing something wrong? I used t taps on one end of the accessory wire and one t tap on the other end without cutting the wire. should I still cut the wire?

[@StephenTack]

Gerson Santiago​ you'll have to cut the accessory wire to put the diode in line... I'd bet that's the problem. If you just turn off the ignition does the radio stay on at all?

[@gabo42013]

Stephen Tack okay I'll try cutting it. When I turn of the ignition the radio does stay on for a few seconds. (~5 seconds)

[@StephenTack]

Ah. Well try adding the diode. If that doesn't work, is probably cause your battery voltage sags a bit too low and browns-out the radio while cranking. Not much can be done for that unless you put a VERY large capacitor (and maybe a big diode) on the battery supply side (yellow wire). 🙄 Good luck!

[@gabo42013]

Stephen Tack I tried cutting the wire. the good news is that the radio still Powers on which let's me know the circuit is correct. the bad news is it still Powers on on crank. So I'll just order more capacitors and try to make the same setup on the constant wire as well when the parts come. thanks! and just out of curiosity, how long does it usually take for the capacitor to charge up? do I have to let it fully charge before cranking?

[@gabo42013]

Stephen Tack So I just realized that after shutting the car off and removing the key, the radio is still on for much longer than before. so now I'm just confused. if it remains on with no accessory voltage. why would it restart on crank?

[@iHopp1764]

What size diode is needed for this? I’m running a 3300uF 16V 13X25 +/-10% -40-+105℃ capacitor and a 1N5353BRLG DIODE ZENER 16V 5W diode. With this installed like you showed, nothing is happening!

[@StephenTack]

Literally any other kind of common diode will work. Just not Zener. 😂 A good one might be a 1N4001.

[@michaelp7052]

To reduce voltage drop, use a Schottky Diode, like the 1N5822

[@StephenTack]

@@michaelp7052 looks like 0.525v voltage drop, vs. like 0.7v 🤷🏼 unless you're operating at the edge of functionality, this shouldn't make much difference. I would still recommend just trying to salvage any (normal, not Zener) diode, and see if that works.

[@prakharmanas1910]

Hey... so I did the acc wire capacitor. Then I added a couple of 4700 uf capacitors on the always on wire. The thing works but only if I crank the car within 2 minutes after shutting it. Any idea why is that and how can i increase the time it keeps on between the cranks?

[@StephenTack]

So shut the engine off, but keep listening to the stereo with the key in ACC mode, and try to start the engine after more than 2 minutes of listening the stereo will be shut down? I'd say your battery may be a little week, and 9400uf isn't big enough (did you add a diode there too?) to supply power while cranking... I forget how big the caps I put on the always on were, but something like 25,000uf x 2, and a diode to prevent the starter from sapping them while cranking.

[@prakharmanas1910]

@@StephenTack Ok great... I'll try a bigger capacitor. I have put a diode there. What diode rating did you put there though? 10amp?

[@StephenTack]

@@prakharmanas1910 just a physically large diode harvested from an old PC power supply. Not sure what specifications.

[@Timothyjpaul]

​@@StephenTack I have the same problem talked about here. When I first added your circuit to to the red wire, all worked great and the radio stayed on during cranking. Then, at some point in the last month or so, the radio stopped staying on while starting the engine. It could be related to having replaced the starter in the car. It may have stopped staying on while cranking after the starter motor was replaced. So now I'd like to add the similar circuit to the yellow wire but I'm having trouble tracking down 25,000uf caps. I found 10,000uf. Any suggestions for where to find the larger, sufficient caps and/or additional guidance on just how large the cap needs to be?

[@StephenTack]

@@Timothyjpaul You can parallel whatever size caps to get enough capacitance , just be sure the voltage rating is at least 15V. Or you could try supercapacitors in series to get the voltage you need. Like this 20F beast: www.ebay.com/itm/16V-20F-Ultracapacitor-Engine-Battery-Starter-Booster-Car-Super-Capacitor-w-L0B5/273865125573 But first thing is to make sure your battery cables have good connections on both ends, and your battery isn't weak.

[@callmeJAF]

help, it still powers off during crank :/ but at least it stays on for 20 seconds when i take key out? so the capacitor is doing something

[@StephenTack]

You will see others with that problem around here. It has to do with the main power to the unit browning-out while cranking the starter. Check your battery and connections, and if they are good options are adding a large capacitor (or bank of capacitors) and a diode that can handle decent amount of power to the yellow power wire as well...

[@callmeJAF]

@@StephenTack My battery was submerged in a lot of acid and was about 20 years old. New battery and it works fine now :)

[@souls_gt7120]

Wow after reading many positive review 😊 I’m feeling so blessed guys, thank for this short video much appreciated 🙏🏼 Can Someone kindly send link or type of Diode I need please??? I’ve found Capacitor on eBay bud need to know which Diode I need ? Thank you

[@StephenTack]

Almost any diode will work. Here are some on Amazon: www.amazon.com/dp/B00W17LOBO

[@vilemvasilenko5250]

Feel free to tell me if I am doing something wrong here. My 2004 Renault laguna shuts the complete ISO cube connector off wheen ideling positive and negative. I already have 2 capacitors installed on both circuits, however since the ground is beeing cut as well, would it help if I simply add an extra solid ground there??? I wonder if anyone faced this problem...???

[@StephenTack]

It's kind of crazy to me that it disconnects the ground. But just at first thought, I don't think that is the problem with the capacitors (and diodes) not working. You mentioned both circuits, do you mean the continuous "battery" supply wire, and the ignition signal wire?

[@vilemvasilenko5250]

@@StephenTack Just figured out one capacitor is weak, but stil 12. 1 Volts it delivers for 5 seconds.... If that could be the problem. Should I wire the negative pole of capacitors to the black cable leading from the ISO cube to the radio, could it work, or its gonna blow the fuse??? Thank you anyway for the video....

[@vilemvasilenko5250]

So I have rebuild the setup. I bought new capacitor 4700uF 16V-much bigger than the old PC source one. New diode 1A 40V and as a ground the black cable from ISO cube and boooom, there we go. It works.Again, many thanxs to your advices and video.

[@nanotech4947]

Very nice explanation video even though its is 6 years old already. I'm wondering if you're still produce this kind of video. I would like to modify my car stereo so that it will delay the shutdown (about 1 min) after i turn off the ignition. This feature can be found on expensive cars (BMW etc) . I thought it is a cool feature to have.

[@StephenTack]

Haven't made many videos since... It's no coincidence that my oldest daughter is almost 6. 😁 The long keep-on could be done with a few large capacitors, but it would probably be better to get a delay module. There's probably one that could also turn the stereo off as soon as the door is opened, like fancy cars do.

[@johnkimtv25]

What is the specs of diode?

[@StephenTack]

For this basically any diode will do. There is an Amazon link pinned in the comments.

[@Mixbag]

i did this but when i turn key to crank it still turns my stereo off. i know iv connected it right because when i remove key the stereo stays on for 10 seconds. im using 3 1000uf 16v caps and a 1N4002 Diode....i cant figure out why its not working. the yellow wire is always live right ? thats what keeps stereo settings and time and so on? i also tried putting the ground of the cap to the car chassis for a good earth but still turns off on crank...i cant get my head round whats happening also have a audio capacitor in the boot for my sound system so it cant be a bad battery..my battery is a decent Bosh aftermarket one too...

[@StephenTack]

+Mix Bag I'd guess when you crank the engine the starter is drawing enough current to pull the voltage to the yellow wire down, and 'brownout' the stereo causing it to turn off. I'd recommend measuring the voltage at the stereo's yellow wire while cranking. You'll need either a good fast reading meter, or a cheap manual ranging/analog meter to catch the voltage dip before the engine starts. Alternatively you could disconnect the coil wire/ignition system power so that the car won't fire up, just crank (don't do this too long, unburnt fuel will build up). If this is the problem you could try putting another (larger) capacitor(s) and/or diode on the yellow wire...this will have the same voltage stabilizing result as the large cap by your amp in the boot. I've found in my car, on cold days, when I restart the engine the stereo's sound drops out very briefly. So my stereo's amp is browning out and shutting down, but it's not enough to turn off the whole stereo, or disconnect bluetooth. Hope you get this figured out. I'd love to know what you find. Cheers!

[@StephenTack]

+Mix Bag BTW, I checked out your channel. Very cool! We have similar interests. Subscribed! ;-)

[@Mixbag]

+Stephen Tack thankyou very much for reply. I have a meter and will take some readings. I also thought about adding caps in the yellow wire. I'll try and get back to you :)

[@Mixbag]

Stephen Tack sorry i didn't see this comment. i have subscribed back to you :) thank by the way! i made a PCB for this project and was thinking on making a video and sharing the PCB files so it makes this mod easier for other people. if i do make a video i will link your video in mine if you like ?

[@StephenTack]

Mix Bag cool. I can see how a PCB could make this easier to get the diode in the right polarity, or if you are using multiple capacitors in parallel. Feel free to link to this video if you like. I enjoy trying to answer questions on these comments, so the more the better. I'll also be making another video, actually installing a capacitor & diode in my old pickup truck.

[@vgnfab]

I did this and I heard a loud pop when I powered it on which I believe to be the diode based on some google searches. I still have enough positive function.. My little circuit is tucked away so it's not worth inspecting it. Some people were talking about an inrush current spec on diodes being the culprit. Can you add any info for me on this? I can at least turn off and on the engine without my stereo cutting out. Luckily my starter is pretty quick with 2 oversized AGM batteries on a Subaru Outback.

[@StephenTack]

How long does the stereo stay on when you turn the key off? If you wanted to limit in-rush current, you could put a resistor in the circuit. I've never popped a diode doing this, so might not be necessary, depending on what kind of diode you use. I just go for random beefy ones salvage from old power supplies.

[@vgnfab]

@@StephenTack 2-3 seconds. I have this ignition signal circuit turning on head unit, a idatalink daughterboard, a DSP and 2 amps. Not sure what sort of current draw that is, or the particulars of signal/ vs. power this line gets used as on them. The resistor is a good idea.

[@StephenTack]

@@vgnfab how big is your capacitor? 2 to 3 seconds isn't bad with all that stuff connected downstream of the diode/capacitor. If it's working that well, you probably didn't blow the diode, the pop may have just been an in-rush surge they caused all the wires to jump a bit? 🤷🏼

[@vgnfab]

@@StephenTack 2200 Micro Farad. Well that would be cool. Nice to know it is at least working. It's just a lot of expensive electronics and a lot of my labor time and planning going into it all to then here a concerning loud pop noise. If you think what I've said implies the Diode must be working, then I'm happy with that. If the Diode did fail, it's possible it failed closed and to where there's still a directional component to it's state. I'd love to know more about the circuit elements interworking, but it's not on my to do list :-)

[@StephenTack]

@@vgnfab Yes, if the diode did fail, it failed short. Which can happen. The secret is, in some cars the diode may be unneeded. If the ignition switch just disconnects the 12V Accessory supply from the battery, and leaves it floating (doesn't ground it), and there's not to much other factory stuff in the car connected in parallel, you don't need the diode. It's there so if these conditions aren't true, the capacitor won't backfeed and discharge very quickly. In fact the diode slightly handicaps this circuit, because it has about a 0.3-0.8v drop across it, so your starting voltage is lower. Since your setup is working, you are good to go. If you want to add keep on time, just put another 2200uF cap in parallel with the current one. Cheers.

[@StephenTack]

Here's a hack that has greatly improved my driving experience the last few days:

[@superjojo555]

hello sir, i used up to 3 10,000uF caps but my headunit (android) only stays on for 3 sec. i also used the diode but still no luck. i also have a sub+amp hooked up but even with disconnecting still no change? whould u or someone else reading this know a solution?

[@StephenTack]

Does it stay on longer with all 3 capacitors or just 1? Are you adding them in parallel or series? Can you test the normal voltage after the diode while it's on? Can you connect a multimeter (set to amps/mA) in line with the red wire, to see how much current the head unit draws on the turn on wire?

[@superjojo555]

@@StephenTack thank you for your fast reply, i put all capacitors in parallel. ACC wire to ground gives 12v after the diode but when i unhooked the capacitors while they where 'full of charge' the three capacitors itself gave about 10v on the multimeter (i dont know if im measuring it the right way tho). i will check how much the headunit draws and i will let u know, thanks again for the response!

[@superjojo555]

@@StephenTack hello sir, i just found out that for some reason the B+(yellow 12v (memory?)) wire was switched with the red ACC wire in one of the iso/din plugs. for a few years ive been using my headunit like this with no problems actually. when i switched the wires back over to the right position, the capacitors worked! turns out 1000uF is enough to keep the head unit on for about 30 sec. thank you for your reply and willingness to help me i really appreciate it. greetings from the netherlands👍

[@johncobb6800]

Not sure if you still watch for comments on here but first of thanks for the video .! I’ve run the circuit in the video and despite my head unit staying on for a good 10 seconds after the key is removed it still restarts on ignition . Any ideas or help appreciated .! I’ve read through all the comments

[@StephenTack]

When cranking the voltage on the yellow wire can be pulled too low to keep the stereo powered on. Things to check: health of the battery, corrosion on the terminals, bad connections anywhere. If you have a good strong, well connected battery, the solution is another diode, and an even larger capacitor (or a bank of them in parallel) on the yellow wire. So when you crank the stereo will be fully powered off the capacitors. You'll need to find either large capacitors to put in parallel, or string together supercapacitors in series to get at least a 15v rating.

[@mrdg123]

Such a pity this didnt work for my Eonon headunit. What else can i try.

[@StephenTack]

Did it stay on at all after turning the car off?

[@jaysongalutan8974]

what is the diode value ty😊

[@StephenTack]

Basically any diode will work for this purpose.

[@rhunt2363]

This worked perfectly on my 97 Miata with a pioneer headunit. I used a Diodes Incorporated 1N4001-T and a Panasonic EEU-FC1C222 2200uf capacitor. Stays on about 5-6 seconds after shut off. Battery is about 3 years old, temperature was about 70 degrees. We'll see how it does in the cold.

[@chrislouisonsr676]

Thanks for the part numbers. I got both from Digikey.com. I picked up three of each (extras for future use) for under $10 including shipping. Miata Is Always The Answer. I have a 2015 NC

[@user-ft6wz8ob8x]

But what happen, if I connect the capacitor and the diode to yellow wire that come from the car battery and negative side of the capacitor to ground ? Does the radio still saving the settings?

[@StephenTack]

The yellow wire provides the bulk of the power, it would still work like normal, and you wouldn't notice any difference with the size of capacitors mentioned here. If you have done this on the red wire as mentioned here, and the radio still shuts off, or reboots when you try to start the car, adding a very large capacitor (or bank of caps) and a diode on the yellow wire can be a solution.

[@user-ft6wz8ob8x]

my problem is, when I try to start the engine, the engine take all the power of the battery and the radio shut down for some seconds, that made to reset the radio whenever try to start the engine and lose the settings and channels . That mean lost of battery power . What to do ?

[@StephenTack]

@@user-ft6wz8ob8x either your stereo is installed wrong (with the yellow wire hooked to an accessory source, not one that's always on), or your battery is getting very weak, or you have bad connections on the battery... Look for battery problems first.

[@srinivasparisara1964]

I followed you & it was a success. But from past few days while cranking radio gets off. I checked capacitors & diode. Both are good. Even after removing key, radio is on for about 15 seconds which indicates that capacitor & diode are good. But why my radio is getting off while starting?

[@StephenTack]

I'd guess your car's battery is getting a little weak, or has corrosion on the terminals. So the main voltage is sagging when you crank the starter, and the stereo doesn't have enough voltage to stay on. Clean the terminals, get the battery tested. And/ot add a LARGE capacitor, and a beefy diode on the yellow wire like you did to the red.

[@luisgordillo1695]

Can i just run an extra wire from my amp capacitor ?? Or is there an unforseen issue with that?? 🤔🤔

[@StephenTack]

Amps (and amp caps) are hooked right to the battery, so that would be an always-on voltage, and you stereo would never turn off.

[@luisgordillo1695]

@@StephenTack whaaa..never knew that! Thought the volt meter on em was also a switch of some kind! Makes perfect sense..thank you! 👍👍

[@chrispage558]

Hi, I've wired it up exactly as per the diagram and put two diodes in circuit. On my test bench it works and I can see the voltage decreasing gradually. However, as soon as I wire it up in the car (taking a feed from a 25amp switched live out the back of the fuse box and the negative going to a direct ground on the chassis), as soon as I shut off the cars power the capacitor appears to instantly drain, straight to 0v as if they weren't even in the circuit (even when not hooked up to the radio)... I can't work out what's going on? Hope you can help!

[@StephenTack]

That is odd, if the delayed turn off works on the bench it should in the car. I'm curious why you have 2 diodes? You should only need 1.

[@chrispage558]

@@StephenTack sorry, one diode and two capacitors. Wasn't thinking when I was writing! Likewise, I've got a variable voltage tester so set it around 12v and it works. Yet in the car it's not interested, really not sure what's going on with this one!

[@StephenTack]

@@chrispage558 were you tested it with the stereo on the bench? If not it could be a strange stereo that draws significant current through the red wire.

[@chrispage558]

@@StephenTack that's the thing, when I tested it on the bench I was just checking the voltage coming out of live. Same again in the car, I didn't have it plugged into anything at all so not to drain the capacitors but still nothing. Thought it might be something you'd experienced before or heard of but not to worry if not! Thanks for your help

[@StephenTack]

@@chrispage558 the supply for the red wire in the car is the same as what you used on the bench. I'd guess either the diode is backward, or died. Or some wire just isn't hooked up right. If you're using a wiring harness adaptor, make sure all the pins are where they should be, they are made incorrectly some times.

[@srinivasparisara1964]

which diode I have to use & if i use higher capacitor will the performance increase?

[@StephenTack]

srinivas ramaiah​ pretty much any normal diode will work...don't use a zener diode, or something special. Yes, the larger the capacitor the longer of a reserve you will have. Be sure it's rated for at least 15v. Cheers!

[@srinivasparisara1964]

Thank you Stephen, This small circuit worked well for me & it solved my restarting problem Thank you once again

[@sdsjoel]

This just works. I did not have a 2200 so I put 2 470's parallel and the unit stays on after switch kill for 3 whole minutes, and yes I timed it.

[@StephenTack]

Nice! Yes I've noticed newer Boss brand stereos must draw almost no current on the red wire. With a 3700uF one didn't turn off for 45 min at least.

[@Arick111]

Tried this with 2 2200uf 16v capacitors in parallel and no diode, so basically the positive side attached to the red wire and the negative to ground. When I hook it up my stereo display is always on. No sound unless the key is in the acc or on position and the sound cuts out when I start the engine but the display stays on. Didn't want to kill my battery so I unhooked the ground wire and it's back to how it was.

[@StephenTack]

I'd say, pop a diode in there...

[@Arick111]

@@StephenTack I appreciate your help. I'll have to try that.

[@deanbelich]

would it need to upscale the capacitor if I am doing this too a Kenwood ddx7015?

[@StephenTack]

+Dean Belich it really depends on how much current the turn-on writer draws. This isn't related to how much wattage there stereo is rated for...just a function of the control circuitry used. If one capacitor doesn't keep the stereo on, try adding another of the same size in parallel.

[@deanbelich]

+Stephen Tack thank-you for that but I did test the battery with a multimeter and found that the voltage drops down to about 10V when cranking the diesel van, in saying that wouldn't i need to have a capacitor and resistor on the constant wire as well as the accessory wire?

[@StephenTack]

That is highly dependant on the architecture of the amplifier in the head unit. Mine occasionally browns-out the amp on very cold days when cranking, but comes right back on without interrupting the music for more than a second. There's only one way to tell if your measured is 10 volts is below the stereo's shut down voltage. Give it a try! If the stereo does shut down while cranking, you'll need to add a much larger capacitor (probably a couple ~10 farad super capacitors in series or something), and likely a high power handling diode as well... also perhaps check the health of your battery, terminal connections, and leads. This is really kind of a separate issue which doesn't plague most vehicles Cheers!

[@deanbelich]

+Stephen Tack what I have purchased is a 4700uf 25v capacitor and a diode IN5404 do you think that would be enough to keep it on? also the battery and van are a couple of months old along with the stereo

[@StephenTack]

That capacitor should be fine for red "turn-on" wire, as described in this video. And that may be all you need to do. If, however the stereo does shut down while cranking, you'll need a second MUCH larger capacitor (or bank of caps), and a beefey diode, on the always-on yellow power wire.

[@StephenTack]

+Ben79k pretty much any common diode will work. good sources are old power supplies, and DC "wall warts" you have languishing in a drawer. Note: different stereos may have different amounts of draw on the turn on wire, so you may need to experiment with different values of capacitors. Hope this works for you as well as it did for me.

[@charminbaer2323]

I need to figure this out for my 2011 Honda Pilot with Nav. I added CarPlay to my factory navigation system via a third party interface adapter from NavTool. Whenever I start the vehicle, the radio turns off/reboots and I have to go thru a series of button presses to get it going again. First, I have to hit "OK" on the nav warning screen before I can do anything. Then I have to press and hold the "Cancel" button for the adapter to switch over to the CarPlay/Android Auto interface and then select CarPlay/AA. (The interface also has an option for 4 cameras, wish it didn't so it would automatically just switch to CarPlay when I hold the "Cancel" button). I also added a wireless CarPlay adapter, so that has to go thru its own boot/connecting process, but that's automatic and can't do anything about that. But yeah, if I turn off the vehicle and then turn it back on, I have to go thru that process all over again. Its not the end of the world but would be nice if I didn't have to do all that. Since my CarPlay interface goes thru the navigation system, I'm worried I'm also gonna have to do this to the navigation DVD player as well to keep it powered during start up.

[@StephenTack]

I would try to see if I could find a wiring schematic. It's almost certainly not going to be standard aftermarket color codes. You'll need to find the accessory turn on wire for at least the nav system.

[@charminbaer2323]

@@StephenTack good point, if I can at least keep the nav powered, I might be able to get away with just doing that part and not the radio as well.

[@Shirehorse73]

Hi, thanks for the video. I'm going to give this a try tomorrow. Please could you tell me if this would work if your using the red wire on a permanent live? Thanks

[@StephenTack]

If the red wire is connected to power that doesn't get cut when the vehicle is off, or while cranking the starter, but the stereo still shuts off (or resets) while cranking, it's likely that the starter is pulling the voltage too low to keep the stereo turned on/powered. You can try this fix first, but will likely need to add a large diode, and a few very large capacitors to the yellow wire (or upstream of the yellow and red if they are tied together)... Or maybe just get a fresh battery, clean off any corrosion, or beef up the size of your wires going to the battery.

[@Shirehorse73]

@@StephenTack Right i'm with you, you've given me a few more pointers, thank you. I'll try your method tomorrow and let you know. Thanks

[@Shirehorse73]

@@StephenTack Please could you tell me if you are using the diode as an insulator in this setup? thanks

[@StephenTack]

@@Shirehorse73 I guess you could call it that. More like a check valve really. The diode makes sure the charge stored in the capacitor doesn't flow backward to power other accessories. In some cars this may not be needed (if the accessory circuit only goes to the stereo, and it's disconnected, not grounded, while cranking), but I've not found a vehicle that didn't need the diode.

[@Shirehorse73]

I understand what you’re saying. Well we tried it today with first of all 2 x 16v 4700uf caps too no avail, we then added 2 more caps the same.. still turned off on crank. I’ve ordered a monster battery this afternoon so will let you know how that goes... thanks for your help

[@badrc350]

Hi, I have a vw polo. I tried it without the diode. It still turns off when I start the car. Could it be that the starter is pulling the power from the cap because I left out the diode? Please help. :(

[@badrc350]

I have a canbus adapter because without it my radio won't turn off even if I pulled out my key.

[@StephenTack]

In my experience most cars/stereos need the diode.

[@badrc350]

@@StephenTack I guess you are right because thinking about it and as you said, it prevents the power from back feeding. I thought this was for safety reasons not to possibly fry stuff, but it actually does play an important role as I very quickly discovered. xD Thanks for the help. :D

[@badrc350]

@@StephenTack Hi, I found out that I had to wire the continuous power to the cap and not signal wire. It worked but when I turned up the volume the diode exploded. :/ It was rated for 50v. I also have a subwoofer. Should i get a bigger one? Please help! :(

[@StephenTack]

@@badrc350 don't worry about the rated voltage of the diode (though 50V seems a bit low, as 300V+ is common), just try to find one that is physically large. Old power supplies usually have some big ones

[@dsquaregroot8932]

Thanks you sooo much for this interesting trick😊😊. It work for me, i didn't expected that. Finally solve this annoying issue. But I noticed that a after turning off the car an remove key , the car head unit stay on for a few 5 second, because the condensator still have a lot off jus to power the head unit. I use a 25v 2200uf condensator for an after market android head unit type. Please let me know If you think there us some thing i could do about that. Again thanks a lot you save me.

[@StephenTack]

Yeah, that's the side effect. There are ways to negate this, but nothing simple or easy. You could reduce the keep-on time (if the car starts quickly) by reducing the size of the capacitor, or putting a high value resistor across it (10k to 100k), or possibly adding another diode in series with the current diode to add another voltage drop. Cheers 👏

[@mikeking5910]

This is a very cool trick. What was the rating for the diode?

[@StephenTack]

I salvaged it from an old PC power supply. So, probably hundreds of volts. If you have a DMM with a diode check function, use that to make sure you're salvaged diode is good... About 0.5-0.8v forward drop should be fine.

[@naamangeist7843]

+Stephen Tack I have a Radio Shack rectifier diode with the following max ratings: 400v peak inverse voltage 1.6v forward voltage drop 1A forward current 30A max surge current 30ma reverse current at PIV Will this work or should I run to Radio Shack and find a more suitable one? Thanks

[@StephenTack]

+110622986866049428290 it will probably work. The high 1.6v forward voltage may cause the stereo to turn off after a shorter delay...depending on what voltage the turn-on wire is looking for... Give it a try, if it doesn't produce desirable results get a normal 'jelly bean' diode, or a larger capacitor. You may not need to return to Radioshark, many devices will have a suitable diode inside. Most 'wall warts,' and any old pc power supplies are likely candidates.

[@StephenTack]

Naaman Geist also, the forward voltage may not be so high at the very low current we are drawing.

[@naamangeist7843]

+Stephen Tack Just completed the job and it works like a charm! Thanks for the info :)

[@payochannel1140]

Diod code? (Specifically)

[@StephenTack]

Really doesn't matter... Basically any little black cylinder with a stripe diode will work.

[@futurecarslondon1109]

Awesome

[@hashimbacang7559]

finally became after a long time looking for a solution. There is only a small problem when using this method, my head unit will turn off after 1 minute after the key is pulled out.can anyone help give a solution?

[@StephenTack]

Use a smaller capacitor, or put a high value resistor across it... I'm guessing 100k 🤷🏼

[@StephenTack]

And/Or you could add more diodes in line, as each has a voltage drop, so you'd be starting with a lower voltage.

[@hashimbacang7559]

I will try, thanks for the help

[@Meihol]

Dear Sir, I want to use my JVC Car Stereo in the Ford Festa Classic model 2012. Please add Capacitor and diode details in your description also so, nontechie person can also buy parts and try to do it by self. I am waiting for ur reply sir.

[@StephenTack]

Cafurty 1N4007 DO-41 Axial Silastic Guard Junction Standard Rectifier Diode (Pack of 20) www.amazon.com/dp/B00W17LOBO

[@StephenTack]

Nichicon UVZ1C222MHD-20 Aluminum Electrolytic Capacitors - Leaded 16V, 2200uF, 12.5 mm x 20 mm, 20% Tolerance, 5LS (Pack of 20) www.amazon.com/dp/B071RTXD64

[@ulixes3650]

It does not work for me completely. The radio stays on for 2 seconds after turning off the ignition, but the radio still restarts when cranking. I am using a 25V 330uF capacitor with 1N4007GP diode. The battery is Topla Energy 12V 45Ah with 420 cranking Amps. The voltage of the battery is 12.41V, with the key on ACC it drops down to 11.60V, when cranking it drops to 9.8V - 9.3V. According to its specs the radio (Pioneer MVH-330DAB) works at 10.8V - 15.1V and it consumes about 0.58A (my testing conditions) with 1/3 volume and around 2A on maximum loudness. So if the voltage drops to 9.8V while cranking when the radio needs at least 10.8V it means that the battery is too weak. I do not want to replace the battery because it is still good. Maybe the next one I buy will be more powerfull, but how much more power do I need? The other solution is to add a diode (how "strong"?) and a high capacitance capacitor in the middle yellow (constant) wire. Again: what capacitance would be enough to hold voltage for about 3 seconds? Also I read somewhere that the power of the battery decreases in the lower temperatures and the power needed to start the car increases in the same conditions. At the moment we are in the end of the winter so I will have to wait until summer to see if there is any difference.

[@StephenTack]

You have a good understanding of the situation. You can use multiple diodes in parallel to handle the power. For the capacitor(s), you'll probably need at least 300,000uF total. You may be able to get this by putting supercapacitors in series to get the voltage rating you need (15v+). You could also look into all the connections to your battery, and starter. Poor contacts will cause voltage drops... Also if you have an older style starter, look into getting a new gear reduction starter, they draw/surge less current.

[@Alex-Zone]

you need 2200 mF capacity, your cap only has 330 mF capacity. thats why it doesnt stay on long enough. edit: oops I mean uF (microFarat)

[@StephenTack]

@@Alex-Zone good catch, if it's not a type-o.

[@thromboid]

Nice trick! It might not work for all stereos, as some use the red ACC wire as the main power source (not just sensing), and the yellow BAT wire just for preserving the memory. In that case, the capacitor probably won't hold enough charge to keep it on during engine start.

[@thromboid]

Haha, just discovered your "YMMV" comment under SHOW MORE. :)

[@StephenTack]

That's true. Any idea want brands do that? I haven't seen it from Pioneer, JBL, or Sonny, in the last 10 years.

[@Gagliano17]

@@StephenTack actually my 2020 pioneer seems to be doing this, i put a frm01 delay relay in between it, but it wont work

[@mrdg123]

This doesn't work on my radio. What did you do to get it working?

[@StephenTack]

@mrdg123 in what way doesn't it work?

[@amankhandelwal1895]

It is not working for me, it is keeping steareo to play 5-6 sec after I remove the key but nit working at the time of start

[@StephenTack]

The starter probably pulls down the battery voltage too low (on the yellow wire) to keep the stereo working. Have a look at the other comments, I've given lots of advice on possible fixes to this.

[@amankhandelwal1895]

@@StephenTack i have also tried connecting one more capacitor to ground and yellow wire, that is also not working, that capacitor will provide the voltage in that case

[@StephenTack]

@@amankhandelwal1895 if you do add capacitors to the yellow wire, they need to be much, much bigger to provide for the high power side of the stereo. You'll also need a beefy diode. The real place to start is making sure your battery terminals are clean, and your battery is good.

[@amankhandelwal1895]

@@StephenTack thanks, i will try that.

[@amankhandelwal1895]

Have replaced the battery but its not working

[@TUANTRAN-rm4xm]

Did not work for hyundai accent HB 2016. Hixxxx

[@StephenTack]

What kind of stereo?

[@TUANTRAN-rm4xm]

​@@StephenTack thanks, I just do it today. I get mistake with the wires color. Your tip is very useful.

[@sanb3586]

Can I do this with cigarette charger ?

[@sanb3586]

And what diod is that name ?

[@StephenTack]

Literally any diode will work.

[@StephenTack]

You can easily make your cigarette lighter stay powered while the car it's off. Just disconnect it from its 12 volt supply, and connected to some supply that is always on (like the radio's yellow wire, if you won't be drawing too much power). I run a heavy wire all the way from the under-hood fuse box, so I can charge anything, anytime.

[@sanb3586]

I want constant Supply even if car is off and locked

[@sanb3586]

And it's must stay on while cranking

[@planetina1145]

Good video. Geek mode activated.

[@HeroClaws]

Yea, didn't work for me, i guess ACC wire draws too much current, i've put 16V 3300uF with the diode and connected it all accordingly. Radio turns on when i turn the key, but when cranking (around 1.5 sec) it reboots. And when i take the key out the radio is still on for good 30 35 seconds. BUT I told myself i had to do it. Today i bought 2 caps 16V 47000UF, put them in parallel, so around 10mF of capacitance. I know that the radio will be on after I unplug the key for my aprox. 1 hour at least. But i want the radio to not reboot when cranking. If this works ill figure out some circuitry when key is pulled out that the radio shuts off. Probably some dsPIC MCU and some firmware, or arduino nano, and i'll figure out the how to flag the moment when the key is out, to possibly just close down the circuit and let them stay charged and not continue to power the radio. Wish me luck haha

[@HeroClaws]

Just to let you know, terminals are not corroded, battery is healthy i have Bosch battery only 1 year old.

[@StephenTack]

Good on you for being persistent. But you're barking up the wrong tree. If the radio stays on for 30 seconds when you turn the key off, it's not the ACC wire, it's the yellow continuous power that is sagging (browning-out the stereo, and causing it to restart) when you crank the engine. Solutions are: 1, check your battery, and the battery connections. A weak battery, or corroded or loose connections will cause more of a voltage drop when cranking. 2, If all connections are good, and the battery is strong, try running a separate supply wire straight from the battery to the stereo, to minimize voltage drop. 3, If this doesn't work, I've had success by putting a large diode, and a very large bank of capacitors on the yellow power wire... So the capacitors can keep the stereo on while cranking. 4, It's also possible that in some older vehicles, a direct drive starter causes a huge load, and a more modern gear reduce starter will more easily crank the engine with less current... This applies to mostly old Ford trucks. Let me know if you figure something out. keep hacking! 🙏

[@StephenTack]

@@HeroClaws Just saw this reply. You have trouble-shot the two most likely culprits... Dedicated supply wire, and/or capacitor bank and diode on the yellow wire are your best bets 🙏

[@HeroClaws]

@@StephenTack Where did you put the large diode on the yellow wire, i've added schematic but im not quite sure its correct.

[@HeroClaws]

​@@StephenTack it wont put the link to the pictures so ill explain schematic. Yellow wire from car - diode -> (anode facing the capacitors) - 2 parallel cap 47000uF on the yellow wire after the diode, and then negative side of caps to GND, and yellow wire to the radio. So when everything is turned off yellow wire will charge caps, when i crank, the diode will prevent the current to flow into the yellow wire (to the car), but they will charge the radio with energy stored to stop it from rebooting.

[@victorsaari1393]

470uF 25v cap, gives me just enough time to crank without shutdown (5sec). sweet.

[@StephenTack]

The inspiration field radiating for your videos was strong enough to motivate me to finish a wee lil' project/hack that I've been thinking about for a while. Thanks ***** & *****.

[@StephenTack]

***** Yeah, my other inspiration is: kzbin.info/www/bejne/oqqphJWjbJ6oeLs

[@aurangzeb6326]

I xxx

[@ashfaqjuna]

16v rating is not safe.. load dump can easily exceed 40V!

[@StephenTack]

Sure, but this is just on the turn on signal, there's a diode, and the ignition disconnects the circuit during cranking.

[@peterarschloch3154]

ALTERNATIVE WAY: hi people i wanna share this. i dont know whether someone suggested it online but im coming out. in most cars you can suply the auxiliary line with power through the lighter socket. best way is to get a lighter socket adapter or slpitter or anything and you disassemble it and you can fit capacitors in them. in my car 4800uf is just about enough to keep it running through the cranking. its without diodes because this eay you cannot add diodes unfortunately. later i switched to a 1fahrad 16v supercapacitor assembly (these are small in size) and it runs for about half minute now. 😁 if you get a lighter socket splitter these have space inside them you can do it without it looking ugly and looking janky.

[@StephenTack]

Why use the lighter for power? There are wires inside the dash designed to supply power to the stereo, making for zero ugly wires showing. 🤷🏼