Keep Vehicle Stereo On When Starting

Use just a capacitor to keep your car (or truck) stereo on - when your ignition switches off the ACC power - while starting your engine. One 16 volt 3300 uf cap sustained the power for about 2 seconds to the ACC . I installed two to get about 4 seconds of power.
The ACC wire wouldn't charge or pass thru the cap to the stereo, but the "always on" power supply did. So I wired the cap from the constant power to the (already connected) ACC line. I thought this would keep the radio on all the time, but it doesn't. When I take the key out, the radio stays on for a few seconds then shuts off.
Exactly what I wanted.
UPDATE 1: At the end of the video I showed adding a USB charging port. If I am charging my phone when I turn the key... the phone takes the voltage stored in the Cap and the stereo does NOT stay on. (boo!). So I have to unplug my phone when starting the car, or wait to plug it in.
UPDATE 2: I later added a subwoofer/amp. I currently have it powered from the same wires shown in the video. That drains the cap as well (even without a phone charging). I'm committed to getting this wired right... but it may be a few weeks before I can. I may just add a toggle switch in the center hole (don't tell my wife). A capacitive touch switch may be in the works as well (so I can hide it).
UPDATE 3: So... yes. I did this wrong. It kinda worked so I thought it was ok. I re-did it with:
1. Negative of capacitor to ground
2. ACC power from vehicle to Positive of capacitor - then to the stereo.
It later found this guy who has the same stereo and did the hack correctly... watch his video too.
• HOW TO: Keep Your Car ...

[@hillmakeitbetter]

UPDATE 1: At the end of the video I showed adding a USB charging port. If I am charging my phone when I turn the key... the phone takes the voltage stored in the Cap and the stereo does NOT stay on. (boo!). So I have to unplug my phone when starting the car, or wait to plug it in. UPDATE 2: I also added a subwoofer/amp. I currently have it powered from the same wires shown in the video. That (without a phone charging) drains the cap as well. I'm committed to getting this wired right... but it may be a few weeks before I can dig back into it. I may just add a toggle switch in the center hole (don't tell my wife). A capacitive touch switch may be in the works as well (so I can hide it).

[@Loyal_Honda_Fan]

Shawn Hill great job man, you know your thing, ima try to do the same as you did, hopefully ^^ So you took 2 capacitors and connected the + sides of them to te yellow (always on) cable and the 2 negative sides on the red ACC cable, did you had to completely cut off any if the cables or did you just stripped them just a little to give contact to the capasitors? Thanks your video is A+++!!! 😃

[@DavetheRaveDinkum]

If u were to add a diode to the accessories power wire between the capacitors and the power supply side of the accessories wire this will prevent voltage being back fed into the accessories circuit allowing the capacitors to only provide power to the head unit, this will fix the issue.

[@johnebenezer3169]

Thanks buddy I searched many videos about this finally I found thank you so much❤❤❤

[@Gthayes]

I followed the link you left at the end of your comments it doesn’t work simply because the power gets drawn out by the negative neutral your way of doing it worked perfectly.

[@hillmakeitbetter]

Interesting. I thought I had something good, then I didn't... but maybe I do? I'm lost LOL.

[@BrainHurricanes]

For keeping the radio on while starting the car, and a few seconds after shut down: 1/2 From the car acc you connect a diode 1A (anode), behind the diode (cathode) connect to radio acc AND to a 3300microF capacitor +, from the cap - connect to ground. This way you prevent other accasories (charging phone) to drain the capacitor. 2/2 Starting can cause the main voltage to drop below 10V, shutting down the radio. For keeping the radio on, with a voltage drop from starting 2/2: After doing 1/2, do the same as above, but for the constant powersupply. Depending on your radio, use a strong enough diode, 7A for example. For capacitor, use a 1F super capacitor instead! If you can't find a cheap 1F 16V, put 3 cheap 1F 5,5V in series (-cap+ -cap+ - cap+ = 16,5V). This way starting the car does not drain the 1F capacitor(s). If you additionally use an amp, nothing changes. But for those who don't know, don't use those small wires for your radio to also power your amp (read amp instructions)! Note that a capacitor alone does NOT prevent current going in the wrong direction!! Conecting a capacitor in the wrong direction can cause it to heat up and explode!

[@iangomes1778]

I was trying this hack since when😭😭thank you sooo much 😍😍😍😍😍

[@MolokoAvenue]

Thank u very much for the video I did the same for my Mazda 3 it works. Big Up👊🏾

[@hillmakeitbetter]

Glad you made it thru and that it helped

[@beppecocozza8686]

Should the capacitor be connected to the yellow wire of the ignition key or to the red wire of the battery?

[@JoshHopkinsYT]

I'm going to try something like this on my car. Got a new stereo and it keeps forgetting my presets and clock during starting. So I'll be adding a capacitor to the constant power wire and prob use a diode to prevent the cap from trying to start my car when starting. Either that, or some high value resistor that would limit the current from going back towards the battery. Also while i'm there I might as well put a capacitor on the accessory too like you did.

[@pankajrohilla4777]

good sir

[@Syphertography]

Top man big thanks

[@hillmakeitbetter]

Glad it helped

[@h2oskiaddict]

The wiring of the capacitors in in this video is wrong and the video should be removed. You DO need a diode! The current can back flow. You know why this didn't work on the ACC side, it's because you have the caps wired wrong.

[@usaryder74]

You are correct. But he has good intentions.

[@jeffsav]

Shawn, great video. I have been having this problem with my 2014 Honda Insight and my Clarion NX404 In dash Nav system for quite some time. I am very good with electronics and am having trouble understanding how the capacitor does not keep the unit on all the time. If you are getting constant voltage from the yellow wire (+12v constant), the cap should be charging and delivering voltage constantly to the red wire (acc Wire) This in theory should make the radio stay on all the time? In your video I see that it's not and am trying to figure out why its not? Can you provide any help here? Thanks so much!

[@hillmakeitbetter]

jeffsav, thanks for the encouragement. I agree with your about getting constant voltage from the yellow wire. I can't remember exactly why it worked OK. I recall putting a meter on the wires and switching the ignition a lot to see what happened. I popped a fuse once, but when the meter gave me what I wanted, I wired it to the stereo and went with it. I'll ask some more tech savvy friends this week and give an update. Also - check out my main comment above about adding the USB port and Sub Amp.

[@jeffsav]

Shawn, thanks for the reply. Going to give it a try. I cant stand the continual resets every time I start the car or even turn the ignition on.Thanks again.

[@StephenTack]

Hi, thanks for the link! Good job hacking the system. I'm intrigued by your first solution....it.shouldn't.work! 🤔 But obviously it does (given no other accessories), so something is going on that deserves further investigation. Cheers!

[@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 capacitor to ground ? Does the radio still saving the settings ?

[@hillmakeitbetter]

not sure I understand 'still save the settings" - do you mean save radio station presets, clock settings, etc if car battery is disconnected?

[@guitarguy3221]

Thanks for this video. This method isnt working for me. My red radio pwr wire has a capacitor and it works as it should I ran a 16V 10,000uF cap on my yellow wire, upstream diode, grounded cap negative, and the radio is struggling to stay on. When cranking & disconnected from radio, the capacitor slowly discharges as it should. When i plug into the radio and crank, the Cap dips to 8V then 3.5V within a second

[@tma208]

Great video! What model is this pioneer head unit?

[@hillmakeitbetter]

thanks... Pioneer FH-X720BT

[@mike712341]

I have the same radio. Does your sound work when it's cold outside. Mine wont work till it warms up. But yeah my radio restarts when I restart my truck but I'll try this and see if it helps. Thanks.

[@hillmakeitbetter]

Temperature doesn't impact it at all. I can't think of an electrical power circuit based on temp 🤔

[@JORJOOOOO]

Will starting the car, while stereo is on, can cause a overvoltage to stereo or a big current and burnt it?

[@hillmakeitbetter]

Don't think so. starting doesn't increase the current to the radio. It takes "some" power to run the radio so cars typically give "all the power" to the start process.

[@kevinw6726]

Wouldn't this cause a parasitic drain with the capacitor wired to constant 12v?

[@hillmakeitbetter]

Good question. My real life response is.. it hasn't cause a problem for me in 3 years. After some research, I found an interesting explanation "Once the capacitor has reached the full voltage of the source, it will stop drawing current from it, and behave essentially as an open-circuit." here... www.allaboutcircuits.com/textbook/direct-current/chpt-16/capacitor-transient-response/

[@thunderbirdizations]

Is yellow wire always on, or is it on only during crank? Like if it’s always on, why would the radio turn off when the car turns off

[@hillmakeitbetter]

The yellow wire is the constant power wire or the 12 volt battery wire. It's always on.

[@DavetheRaveDinkum]

Exactly my thoughts, this whole thing working the way it does makes no sense. The yellow wire is B+ (12v constant) this means the capacitors will always be receiving battery voltage meaning they should never lose power unless the power drain is above the capacity of the battery, draining the capacitors faster than they can recharge. If the capacitors are constantly receiving battery voltage then they should continue to constantly supply that voltage even when the car is off and the key is out of the ignition. I don't understand how it is possible that they are depleting while connected to B+ 🤔 Something else is going on here, perhaps something to do with the existing factory configuration or some kind of sorcery 😂

[@mdkhusaini]

How about im using 3300uf 50v single cap, will it worked?

[@hillmakeitbetter]

I'm not sure if the 50v cap will charge, but worth a try. LMK

[@shellemshiu]

I'm going to try

[@annapurnahospitality4616]

Hi my car FM is run while engine is stop ..when engine start FM is not working ..it too noisey ,no clear voice ..please advice

[@hillmakeitbetter]

I don't have a good answer but it might be a bad ground wire. Search KZbin for "car stereo engine nose."

[@jidi1207]

arent negative of the capacitor suppose to connect to the ground?

[@hillmakeitbetter]

So... yes. I did this wrong. It kinda worked so I thought it was ok. I need to redo it with: 1. Negative of capacitor to ground 2. ACC power from vehicle to Positive of capacitor - then to the stereo. 3. I'm going to try adding a diode as well to keep my USB port from draining the cap. It looks like this guy has the same stereo and did the hack correctly... kzbin.info/www/bejne/naXHZ5d3rNZmh7sm29s

[@h2oskiaddict]

Yes they are. This video is bad information and should be removed.

[@Tobra1277]

One question.. how long those caps needs to be charged for the first ACC/ON in order to have enough power for 4 secs before starting the engine? In my opinion it's impossible to have it works if you start the engine in a rush, CMIIW

[@hillmakeitbetter]

Good question. Googling "How Long Does It Take to Charge a Capacitor?" would be better than if I tried to rephrase what I found. My main purpose for this is to keep the stereo on, like after I have stopped for gas. So it's had plenty of time to charge. Sorry I couldn't help more.

[@Tobra1277]

​@@hillmakeitbetter Okay, it means it's only works as long as you don't take the key out, right? Anyway thanks for your explanation, quite useful

[@hillmakeitbetter]

@@Tobra1277 While starting, the vehicle cuts stereo power. This hack helps maintain power for a few seconds while starting. Mine stays on a few seconds after I remove the key.

[@pdurand63]

That size cap will take about 2 seconds to charge up

[@pdurand63]

It doesn't matter how long your stereo stays on for after you take your key out of the ignition mine stays on for 15 minutes and every time I start my car is still cuts my radio off so it really doesn't matter how long your stereo stays on afterwards it's the capacitor stored the voltage that is draining into your radio that is what keeps it on. Your ignition is still going to cut off the voltage to that radio it's the capacitor that's going to help it keep it on and the other kid was right you do need a diode cuz there is backflow think of it as a double check valve in water it can go one way and not the other it does backflow so you do need a diode and it would cause a pair of acidic draw if you don't use the diode

[@victorsaari1393]

wow, those are big caps. in my case, only one 470uF 25v cap was sufficient to give me 5 sec of run time. just enough to crank without reboot. I guess it depends on the input resistance of the stereo ACC line. mine is close to 8k ohm.

[@hillmakeitbetter]

I started with 1 cap but doubled it to get a few more seconds. I think its because I did something wrong or other things drain the cap.

[@Mikkel111]

@@hillmakeitbetter Do the lights stay on in the dash or the exterior lights?

[@hillmakeitbetter]

@@Mikkel111 No. This mod only impacts the stereo.

[@nissiangavin7280]

Mine stays off though once I crank my car pls help

[@bphillipstn]

you would think the radio would turn off immediately when cutting the key off. Since there is no longer 12v on the yellow wire. I guess the radio will run with only 12v on the accessory wire.

[@hillmakeitbetter]

The idea is that the Capacitor keeps 12vdc to the signal wire for a few seconds, which tells the radio to stay on.

[@tomasmatulaitis1810]

🤝

[@karlomendoza8288]

so confused.. i draw what u did and it's impossible to work. do you have schematcs

[@hillmakeitbetter]

Karlo, sorry for the confusion. I added an "Update 3" to the main description with wiring notes. There is also a link to a similar video from someone else who explains this better. I hope this helps.

[@karlomendoza8288]

Shawn Hill thats ok. wer is update 3

[@hillmakeitbetter]

@@karlomendoza8288 It's in the main description but I'm pasting it here to UPDATE 3: So... yes. I did this wrong. It kinda worked so I thought it was ok. I re-did it with: 1. Negative of capacitor to ground 2. ACC power from vehicle to Positive of capacitor - then to the stereo. I later found this guy who has the same stereo and did the hack correctly... watch his video too. kzbin.info/www/bejne/naXHZ5d3rNZmh7sm29s

[@BadalSingh-cj2do]

My car strio always on even I turn off my phone please tell me solutions

[@hillmakeitbetter]

Your phone shouldn't control three stereo power. The stereo will stay on if you still have your car key in the On / Acc position.

[@DavetheRaveDinkum]

I dont understand how the capacitors aren't being constantly charged if they are connected to 12v constant? Even if u turn off accessories and the capacitors were to deplete, my understanding is that they would just charge up again and turn the head unit back on. I really want to work this out lol.

[@hillmakeitbetter]

Check out the Updates in the description & the video I linked to as well. I think Stephen Tack has a better illustration.

[@DavetheRaveDinkum]

@@hillmakeitbetter cheers, I'm keen to get to the bottom of this. With my current understanding it goes against the laws of physics 🤣

[@DavetheRaveDinkum]

@@hillmakeitbetter also there isn't another setup like urs, that I have seen online, nor would I ever set it up the way U did based on my understanding of electronics and physics. Ur setup is all wrong, yet it works 🤔🤪 it's magnificent! ❤️

[@AndreMartinsSilva]

Could you send me the project? Please

[@hillmakeitbetter]

I don't have any other project documentation or info. This other video is similar and has a good wiring diagram. kzbin.info/www/bejne/naXHZ5d3rNZmh7sm29s

[@dinny420]

Hi Shawn.. can u plz share the capacitor sepc..

[@hillmakeitbetter]

I used two 16 volt 3300 uf caps, but you may want more capacity. Just be sure to use 16v.

[@dinny420]

@@hillmakeitbetter thanks bro... cheers!!

[@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 supply the auxiliary line with power through the lighter socket. best way is to get a lighter socket adapter or splitter or anything and you disassemble and you can fit capacitors in them. or if you do it janky you can add these on the outside or just hack a capacitor onto a plug. in my car 4800uf is just about enough to keep it running through the cranking. (2-3sec) its without diodes because this way you cannot add diodes unfortunately. it wastes some power elsewhere i switched to a 16v 1fahrad supercapacitor assembly (these are small in size still) and it runs for about half a minute now 😁

[@hillmakeitbetter]

glad its working. i need to up mine to run longer & will try that 1f

[@Loyal_Honda_Fan]

Wooow hahaha, can you be more specific with what you ve done with the cables? ^^

[@subashnesh]

What model stereo is that

[@hillmakeitbetter]

Pioneer FH-X720BT 2-DIN CD Receiver with Mixtrax and Bluetooth

[@donwolfjr1]

Well, Please keep us posted because this didn't work for my system...

[@hillmakeitbetter]

In one of my updates, I added a link to a video from a guy who has the same stereo and did the hack correctly... watch his video too. kzbin.info/www/bejne/naXHZ5d3rNZmh7sm29s

[@h2oskiaddict]

Because the video is wrong. The wiring is not correct. @Shawn Hill remove this video man. Or remake it correctly.

[@vgnfab]

Sorry, this is often unwanted advise, but I had your same lisp growing up and years of speech therapy did nothing for me. My grandpa fixed it over the phone by simply telling me to say the F sound. Then keep your mouth in that position and transition to S. Your tongue moves from the back to the front as the only difference f to s. Hope that helps.

[@hillmakeitbetter]

I hear ya. Worked on it for years as a kid. I forget about it now.

[@thunderbirdizations]

Please read below for the correct way to do this. These capacitors have nowhere near the necessary energy to run a radio for 2-6 seconds. Method 1: Tap into “Start/Crank” wire, run it to radio or radio’s relay. Relay is preferred; USE DIODE. Method 2: Buy 1-2 sets of 6x 10-farad super-capacitors with board. If using 2 or more, connect them in parallel. Connect positive to radio or radio’s relay (preferred); *consider using resistor*. If using anything more than 10-farad super-capacitors (eg 500f capacitors): 1) DO NOT link it to the relays; this will drain your battery. 2) MAKE SURE TO USE CORRECT RESISTORS; you will fry your wires otherwise. 3) MAKE SURE TO USE DIODES *TO* radio/electronics. You will fry your electronics/dash wiring otherwise (compounded even more if you don’t select correct resistor(s) )

[@thunderbirdizations]

Building (or, overbuilding) this for my center console. Will upload what I have when I find time. Sometimes, burning a new tune onto my engine shuts it off. My ECU and Tuning computer stays on. When I crank, my tuning computer restarts. Very annoying. Also don’t like waiting for my radio Bluetooth to reconnect