The EASIEST way to test parasitic draw

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Күн бұрын

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@classiccarmaintenance 6 ай бұрын

NOTE: If you have a modern car with electronics or accessories that need continuous power supply to not lose data and settings, you need to hook up these electronics and/or accessories to an external power source to power them before disconnecting the battery. Always first check your car's owners manual and your car accessories' owners manuals for instructions. However, it’s important to know that if you use an external power source, you won’t be able to tell if the parasitic draw comes from any of these hooked up accessories or electronics.

@stevet603 5 ай бұрын

I disconnected the positive from the battery terminal to the fusebox at the battery terminal. I thought the problem might of been where the cable joins under the fusebox, but couldn't figure out how to remove the box to inspect the underneath. I think I have an alternator issue, because as soon as I squirted some (lots) of WD into it the multimeter started reading milliamps instead of amps. A couple of days left overnight the battery showed as 12.68V so thought I had tracked it down, but today it was down to 12.35V (after locking up and leaving for an hour).

@classiccarmaintenance 5 ай бұрын

@@stevet603 WD40 is an insulator fluid, meaning that it can temporarily solve an issue with an internal short somewhere in your alternator. If the WD40 fluid gets in between two rubbing wires or a damaged wire and a metal surface which cause the short/parasitic draw, it can temporarily solve/mask that issue. The first and easiest thing you can do to see if you have an alternator issue, is to disconnect your alternator right after having measured your car battery voltage. Then leave your car locked overnight with all electronics turned off, and measure the battery voltage again in the morning. If your battery voltage is much lower than the previous day, your alternator probably isn’t the (main) cause. If your car battery reads about the same voltage, it’s highly likely your alternator is faulty and needs to be replaced. In case this test indicates that your alternator isn’t the (main) issue, the next thing on your checklist, based on your findings, should probably be to find a way to disconnect and test the cable between the battery terminal and the fusebox. IMPORTANT: Do not attempt to start or drive your vehicle while your alternator is disconnected, as this could damage your alternator!

@stevet603 5 ай бұрын

@@classiccarmaintenance Thanks for that. some days, it holds 12.6V, other day down to 8V overnight. where do I disconnect the alernator please?

@classiccarmaintenance 5 ай бұрын

@@stevet603 Disconnect all electrical wires that connect to the alternator, but make sure to first take pictures so you can reconnect them exactly as they were afterwards. Careful: do not start the engine or drive your car with the alternator wires disconnected to prevent damaging your alternator.

@stevet603 5 ай бұрын

@@classiccarmaintenance Thanks again :) looks like I have to dismantle other bits to get to the connections :(

@mark-1rc502 8 ай бұрын

Thank you for the most easiest non tech nerd way of explaining how to do it . 🙏

@classiccarmaintenance 8 ай бұрын

Thrilled to hear you found it easy to follow! Thanks for the support and happy motoring!

@tonymaxwell9460 8 ай бұрын

Hell yea!! Finally, a video I can understand. Thank you!

@classiccarmaintenance 8 ай бұрын

You're welcome! Glad you liked it!

@jerrydavis6995 7 ай бұрын

@@classiccarmaintenance@classiccarmaintenance I

@KC9IUX17 6 ай бұрын

No change up, no curveball, nothing but FUCKIN GAS GOAT

@jmer3536 19 күн бұрын

This is the best Ive seen explaining what a parasitic draw is AND how to find it with a Multimeter

@classiccarmaintenance 18 күн бұрын

Thank you, appreciate it!

@PersonalRobotJesus 2 ай бұрын

Y'all consistently put out the best, easiest to follow DIY vids for auto maintenance I've ever seen. Thanks for keeping it simple and direct!

@classiccarmaintenance 2 ай бұрын

Thanks so much for your support! Really appreciate it. It keeps us motivated to hear feedback like this. We'll definitely keep the videos coming. Great to have you on board!

@Snoop3x 5 ай бұрын

You, sir, are a scholar and a gentleman. Thank you

@classiccarmaintenance 5 ай бұрын

Thanks, appreciate it!

@tnoiset9085 Ай бұрын

Yay on the TJ! My battery has been going dead on my TJ after a few days of not driving it, which brought me to this video. I found where someone, through the years, had a couple of wires jammed into a couple of fuses/slots. Guess I am about to find out what those powered, hopefully nothing important, and perhaps my issue will go away. If not, you gave the perfect solution. Thank You!

@classiccarmaintenance Ай бұрын

Glad you liked it! Thanks for watching!

@greglonnon 2 ай бұрын

lead clamps and putting the meter on the windshield is a great idea. Thanks!

@classiccarmaintenance 2 ай бұрын

You're welcome. Thanks for watching!

@razvanandreiparamon7762 8 ай бұрын

Thanks man, really helpful and straightforward

@classiccarmaintenance 8 ай бұрын

You're welcome! Glad you liked it!

@championsartain3061 Ай бұрын

What a fantastic video. Thank you very much for this good sir! Twas informative and concise, I evn got a feeling of sense of humor. Great articulation and teaching presence. A++

@classiccarmaintenance Ай бұрын

Thank you for the kind words, appreciate it!

@ElGatoTerco 3 күн бұрын

Wow, dude thank you soo much! This video was simple! Now once I find the part of the wiring that has a draw, I'll just have to fenagle with it to find it. In my case, I'm fairly certain the '01 wrangler I just bought has some wires shorting out from some aftermarket headlights it used to have.

@classiccarmaintenance Күн бұрын

Thank you, appreciate it!

@HughDuncan-od8sq 6 ай бұрын

Beautifully done, thank you, now consider myself an expert in parasitic draw...

@classiccarmaintenance 6 ай бұрын

Thanks! Glad you liked it!

@bobkernahan6340 10 ай бұрын

great video and to the point thank you

@classiccarmaintenance 9 ай бұрын

Thanks, appreciate it!

@alext8828 8 ай бұрын

Excellent video. Very clearly explained.

@classiccarmaintenance 8 ай бұрын

Glad you liked it!

@ThadeousMonkey 7 ай бұрын

Thank you!!! I watched several videos for this and you best described what to do and what to look for.

@classiccarmaintenance 7 ай бұрын

Glad you liked it!

@jackflash5659 Ай бұрын

Very considerate to highlight the importance of safety at the beginning of this video. Terrific tutorial. To the point without any b.s. Liked and subscribed. Thank you and keep up the good work!

@classiccarmaintenance 29 күн бұрын

Thank you for the support, it means a lot!

@foggymtnbreakdown 5 ай бұрын

Your meter may confuse some viewers who have a different meter. On your meter, the switch is turned to the symbol for AC amps, which has the sine wave line under the solid line, but the digital display shows DC amps, which has the symbol with the dashed straight line under the solid line. I have 3 multimeters where the rotary switch can be set to DC amps or AC amps. If I did it like you did it on the video, I would be trying to measure AC amps instead of DC amps. I am assuming that the "func" button on your meter selects between AC amps and DC amps. Your video helped me a lot. Thanks for taking the time to post it!

@classiccarmaintenance 5 ай бұрын

You are correct! Our multimeter has a single symbol for both AC and DC amps, which we can switch between by pressing the FUNC button. If you have a multimeter with seperate symbols on the rotary switch, you have to turn it to the DC symbol with the dashed straight line under the solid straight line. Thanks for the feedback!

@ronaldochambers1107 8 ай бұрын

An excellent video, brief but detailed. I understand with modern cars with their numerous computers it's even better to check for any voltage drop across a fuse using a second multimeter across the small terminals on each fuse. Thus the fuses are not removed which could "wake up" any computers which take a while to "go to sleep" when the fuse is replaced.

@classiccarmaintenance 8 ай бұрын

Hi, Thanks for your reply, appreciate it! You’re absolutely right that there are other ways to test for parasitic draw, like measuring and investigating the relation between voltage drop and current draw by testing over the fuses while in situ. However, this involves testing and calibrating your test equipment before you start, researching “normal” power consumption of each circuit on your specific vehicle (taking into account aftermarket equipment), closing or latching all door locks and avoiding anything that might trigger a sensor that could “wake up” the car’s computer(s). To be absolutely sure that the computer(s) are “asleep”, with the latest cars you might have to wait up to 2 hours. To interpret the readings you get over the fuses, you would have to use a comparison chart, specific to the type of OEM fuses that are used in your vehicle. Aftermarket (replacement) fuses that often look exactly like the OEM ones might give different values and will be hard to guesstimate. That being said, these tests are very specific to the brand and model of your vehicle and to do it right, you need access to the correct information and experience with this exact type or family of vehicles. Our aim is to empower people on how to do a basic DIY test for parasitic draw that anyone can do, with a small budget using a simple cheap multimeter, without needing expensive equipment. Although it’s a basic test, and it may not be perfect, it gets the job done and it will eliminate all major parasitic draws in minutes.

@jameswalley7234 8 ай бұрын

I had to open my door to get to the fuses, which jumps the lights and then waited for them to stop to get an accurate reading. I pulled a fuse for my seat and saw a change but after putting the fuse back the reading was normal.

@ballhawk387 4 ай бұрын

Right to the point, excellent!

@classiccarmaintenance 4 ай бұрын

Thanks! Appreciate it!

@scheuerle2 Күн бұрын

Thank you for this!

@classiccarmaintenance 17 сағат бұрын

You're welcome, thanks for watching!

@bridgetlg 2 ай бұрын

Excellent and simple explanation Thanks. I needed quick a refresher course

@classiccarmaintenance 2 ай бұрын

Glad you found it helpful! Thanks for watching!

@jennypenny812 Сағат бұрын

Thanks for the video, I had a question. My car seems to short circuit when it rains, lights go crazy, Locks click on and off on their own, and even the trunk opens on its own, and this drains the battery, last time it killed it completely. I have a mini cooper r56 2009. Will this also work for my situation? I am guessing I have to wait till the car gets wet and the symptoms are showing, since when the car is dry, none of this happens... any tips? Thanks

@caznilo33 Ай бұрын

Best video in a while

@classiccarmaintenance Ай бұрын

Glad you liked it!

@Shadybiz1 3 ай бұрын

Thank you for the video! Just bought a new (to me) car a month ago. Pretty darn sure that there is a parasitic draw, most likely because of the stock radio. Just ordered one of these, so I'll know for sure soon enough!

@classiccarmaintenance 3 ай бұрын

Glad you found the video helpful! Sounds like you're on the right track. Good luck with the test, hope you get it sorted out quickly!

@Shadybiz1 3 ай бұрын

@@classiccarmaintenance Oh I'm on the right track alright...on the right track to justifying the purchase of a new head unit and a new amp to replace the stock ones of each!! (...I was going to do that anyway, :))

@classiccarmaintenance 3 ай бұрын

Sounds like a perfect excuse to upgrade! 😄 New gear always makes the project more fun, enjoy the new setup!

@TheStoryof6strings 16 күн бұрын

I still have and use that same radio!

@siarlbychan 4 ай бұрын

Excellent! Straight to the point. Thank you. I had never heard of parasitic draw before today. I just purchased a 2019 RAM 1500. This is the first vehicle I've ever owned that has this much electronics. I love it but I also love my 1989 Toyota pick up. I can replace every part under the hood and see everything. So after turning off the ignition in the Ram 1500 I have noticed that things are still happening under the front dash. Humming, ports opening closing because of the Star Wars-ish whoosh (no exaggeration). It sounds like the opening and closing of the doors on the Death Star. So it made me wonder about power usage when the battery is not being charged. Every time I open a door, lights come on, the screen comes on, and they stay on for what seems a minute or so. So it's got to be a drain at some point right? Doing research today, I found out that it is called parasitic draw and there's an allowable amount of it! I wish it was zero. I'm old school and very utilitarian. I like all the bells and whistles but let's not get crazy. Thanks for the video!

@classiccarmaintenance 4 ай бұрын

Thanks a lot! Glad you found it useful.

@rolanddejesus8685 3 ай бұрын

thank you very much sir , very clear explanation.

@classiccarmaintenance 3 ай бұрын

You're very welcome! Glad the explanation was clear for you!

@CalebHigginbotham 5 ай бұрын

very informative and condensed video. thanks!

@classiccarmaintenance 5 ай бұрын

Thanks! Glad you liked it!

@kennydiel4797 6 ай бұрын

Great video, simple to the point. Easy to understand. Finally not all the hoo-ha bla bla bla stuff.

@classiccarmaintenance 6 ай бұрын

Thanks a lot! Glad you enjoyed the straightforward approach. Appreciate your support!

@trotion 4 ай бұрын

Very informative video, good work! Helped me

@classiccarmaintenance 4 ай бұрын

Glad you liked it! More to come, stay tuned.

@MS-kf5rr 4 ай бұрын

Thanks for the knowledge.

@classiccarmaintenance 4 ай бұрын

Appreciate it! Thanks for watching.

@drraspberry 5 ай бұрын

I cannot thank you enough 🙏🏻🙏🏻🙏🏻

@classiccarmaintenance 5 ай бұрын

Glad you liked it!

@davidlamb2538 4 ай бұрын

Great Great video. Thank you!

@classiccarmaintenance 4 ай бұрын

You're welcome!

@max-tl1dr Ай бұрын

Thank you for this video. I have the same meter. I have been having trouble with intermittent battery drain on my 2015 civic. It happens randomly where I go out to the car and there is no power and I have to jump the battery. I did this test and it read 0.012 which I believe is in normal range right? I pulled some fuses anyway and when I pulled the "backup" fuse the meter went down to 0. There was no draw at all from the battery. Is this normal?

@classiccarmaintenance Ай бұрын

Any draw under 50 miliamps is considered normal, so it appears that your conclusion that you don't have a parasitic draw is correct. If your car battery can't hold its' voltage but you don't have a parasitic draw, most likely your battery is bad and needs replacing. To make sure, check out our video about how to test your car battery which you can find on our channel: kzbin.info/www/bejne/fZaofqWGhK5jrq8. If your car battery passes the battery tests though, you might want to investigate your cars' electronics and car computer for erratic activity. If it turns on and off randomly for example, that might cause the occasional parasitic draw you're describing. In this case you might want to consult a certified Honda technician to sort out possible software-related issues.

@CryTwink 24 күн бұрын

I love Jack

@Ken-gv2ql 9 күн бұрын

The battery in my car is in the trunk. Could I run long wires from the battery (one wire on the red terminal and another wire on the disconnected black cable) to the multimeter which would be held near each fuse box?

@classiccarmaintenance 7 күн бұрын

You sure can! This will speed up the process of finding the right fuse(s) as you don't need to run back and forth to view your multimeters' readings. But watch out: you mentioned connecting the multimeter between the positive (red) terminal and the disconnected negative (black) cable, which is incorrect. You need to connect the multimeter to the disconnected negative (black) battery cable with one probe and to the negative (black) battery terminal with the other probe, otherwise the test won't work.

@Ken-gv2ql 7 күн бұрын

@@classiccarmaintenance Thanks for the help. I should pay more attention😀

@albertoguerra3995 Ай бұрын

So what do you do now do I change the fuse with a new one or buy new radio?

@classiccarmaintenance Ай бұрын

No, the fuse itself isn’t the problem. Pulling the fuses is just a way to easily locate on which circuit the parasitic draw is located. If you pull the fuse that protects the radio only, for example, and the parasitic draw disappears, you know the radio or its wiring is causing a parasitic draw. The radio might not be switched off, as shown in our simulation, or there might be a damaged wire, or the radio itself might be faulty. Once you’ve determined by elimination which part(s) is(are) causing a parasitic draw, you know what needs to be repaired or replaced.

@Mike-yq6jg Ай бұрын

I have a 1990 g wagon and when I turn the lights on the side indicators have a slight glow ,any idea

@johnpilkington6879 3 ай бұрын

Another tip is fit a buzzer between the earth terminal then when you pull the suspect fuse the buzzer will go quiet instead of keep lookin up at the multimeter screen 😎

@classiccarmaintenance 3 ай бұрын

This could work, however, the buzzer will only sound when it gets enough power. Depending on how small the parasitic draw is, the buzzer won’t sound at all or too faint to hear it. So, in our opinion, that’s too many unknowns.

@Artur-Itas 8 ай бұрын

INTERESTING SOMETHING HAS BEEN SEVERLY DRAINING THE POWER FROM MY CAR BATTERY LIKE A VAMPIRE IN THE DESERT. THE BATTERY CAN'T HOLD A CHARGE TO SAVE IT'S LIFE. HOPEFULLY THE MECHANIC CAN FIX IT, CAN'T WAIT TO FIND OUT THE CAUSE. IT IS SO ANNOYING.

@tiffanyv4205 7 ай бұрын

Did you ever find out??

@kbengson9163 2 ай бұрын

@@tiffanyv4205Looks like the vampire draw got Artur-itas after it sucked the last bit of life out of his battery,the mechanic he took it to,and all the other techs in the garage. No one has seen or heard from them in months & months 😂

@Autofixgarage-ng 4 ай бұрын

Hope removing fuse & replacing method won't give wrong readings in a case where a removed fuse controlling a particular component will make d certain modules go to sleep.

@classiccarmaintenance 4 ай бұрын

That's why with modern cars you have to wait half an hour or sometimes even longer for the computer and electronics to go into sleep mode before performing this test.

@oncallguy 10 ай бұрын

thank you

@classiccarmaintenance 10 ай бұрын

Glad you liked it!

@DetailDuck 6 ай бұрын

If I hook my multimeter up like you did, should I still be getting power to the car?

@classiccarmaintenance 6 ай бұрын

Yes, the power will run through the multimeter but will be limited by the fuses inside your specific multimeter. If the power demand surpasses the capacity of the fuse(s) in your multimeter, the fuse(s) will blow. For example, this can happen if you try to start your car.

@gosser66 2 ай бұрын

Just to confirm, you mentioned that the battery needs to have a full charge in order to test for parasitic draw. My battery is only reading 10.7v, and my amp meter isn't picking up any draw whatsoever. Sound about right?

@classiccarmaintenance 2 ай бұрын

It's a good sign that your multimeter isn't picking up any parasitic draw, but for an accurate reading you should always first charge your car battery fully before checking for parasitic draw.

@theycallmegeeg 2 ай бұрын

Once you find the parasitic draw, do you change the fuse?

@classiccarmaintenance 2 ай бұрын

@zeeshawnali4078 5 ай бұрын

In one shot you have the negative lead from the multimeter on the battery terminal and another you have the positive, does it matter which way you do it?

@classiccarmaintenance 5 ай бұрын

No this does not make a difference. It will only change the "direction" electricity flows through the multimeter, displaying the parasitic draw as a positive or negative number. It does not change the measured value itself. If you connect the multimeter between the negative battery terminal and the battery cable with the black test lead on the battery terminal, it will display the parasitic draw as a positive number. Put the red test lead on the negative battery terminal and the black test lead on the battery cable and it will show the exact same parasitic draw, but as a negative number with a "-" sign in front of it.

@zeeshawnali4078 5 ай бұрын

@@classiccarmaintenance thanks!

@LKahlilR 6 ай бұрын

What if you need a certian accessory to be on all the time? Like a third party car alarm, gps tracker and dashcam running the continous draw from the battery?

@classiccarmaintenance 6 ай бұрын

In that case you need to hook up these accessories to an external power source to power them before disconnecting the battery. We like to use a car battery charger that has a supply mode like this one amzn.to/3wxSJRg. Always first check your car accessories’ owners manual for instructions. However, it’s important to know that if you use an external power source, you won’t be able to tell if the parasitic draw comes from any of these hooked up accessories.

@marifkhan2003 6 ай бұрын

How we can bring hybrid car in accessories mode without connecting negative battery cable? Or is there a different method to test amps drop in hybrid cars?

@classiccarmaintenance 6 ай бұрын

Thank you for your question! For hybrid cars, due to the complexity of their electrical systems, it's best to consult a professional licensed mechanic who is trained on your specific brand and model. They have the specialized knowledge and tools to safely and accurately diagnose and address any issues, without causing damage.

@ChrisDonoho 3 ай бұрын

When I remove the negative power cable from the battery no power is going to the vehicle. Therefore I have no draw, even when I try to. The radio will not come on if the battery is disconnected. How did you get the radio to come on when the battery was disconnected?

@classiccarmaintenance 3 ай бұрын

When you hook up the multimeter between the negative battery terminal and the black battery cable, it functions as a bridge allowing power through. This, however, is limited by your multimeters' internal fuse(s). If you turn on too much electrical stuff and draw too much power, its fuse(s) will blow and you'll have to replace them.

@AaronFlynn-s8z 3 ай бұрын

How is your radio on if you have negative disconnected?

@classiccarmaintenance 3 ай бұрын

@kameronselvey4723 17 сағат бұрын

So would I need to replace the fuse?

@classiccarmaintenance 17 сағат бұрын

@kameronselvey4723 16 сағат бұрын

@ makes sense. So I know it’s my 12v plug. If I leave my stuff plugged it my car dies in about an hour and a half. Not fully just not enough to start. This just started happening recently so would the whole 12v unit need replaced somehow?

@IsaiahChapter53isAboutJesus Ай бұрын

Does this have to done on amps? Could it be done on DC Volts?

@classiccarmaintenance Ай бұрын

No, it has to be done with a multimeter in the amps setting.

@IsaiahChapter53isAboutJesus Ай бұрын

@classiccarmaintenance Is it too difficult to explain why? I'm trying to learn electrical and I know it can be difficult.

@classiccarmaintenance Ай бұрын

In our video we're demonstrating the simplest way to test for a parasitic draw, with an amp draw test using a simple multimeter. Of course you could test for parasitic draw using volts by performing a different test, but you would need a very accurate professional multimeter to measure voltage drop across fuses and compare the measured values to a fuse voltage drop chart. This however is much more involved and time consuming as a difference of even 0.1 milivolt (which is 1/10,000th of a volt) can mean the difference between having a parasitic draw or not. That's why it's much easier to perform a parasitic draw test by measuring in miliamps, just like we demonstrate in our video.

@erichernandez9751 13 күн бұрын

Hi, I have a toyota corolla 2017 manual transmission. It draws 140mA with the alarm activated all doors and lights closed. It is the dome fuse that draws 60mA out of the 140mA. It the turns to 10mA when a relay clicks after 20 mins. Is this normal? I hope I get noticed..

@classiccarmaintenance 13 күн бұрын

You're good, that's perfectly normal for modern vehicles. The parasitic draw of 140 milliamps you measured in the beginning is because the dome light was still on and because the computer was still running in the background. Once the dome light goes out and the electronics go to sleep (the relay that clicks) you have a draw of 10 milliamps which is well below the acceptable 50 milliamps. That's why we said in the video that with modern cars you might have to wait half an hour or longer to perform this test as the cars' computer needs to go to sleep first.

@erichernandez9751 13 күн бұрын

@classiccarmaintenance Thank you so much, that really eased my mind. You are very helpful! I hope you get tenfolds of followers and subscribers!

@classiccarmaintenance 11 күн бұрын

Thank you for the kind words, appreciate the support!

@agde0968 2 ай бұрын

Thanks bear in mind minimal battery drain can give many months of”Thrustration” The culprit a very small car battery and an aftermarket hardwire to a Nextcam dashcam. The manufacturer may say it won’t cause issues , for me it’s cost £60 plus many hours of work and a non starter😿🤐🥵

@TheChunckymunkey 3 ай бұрын

Would you just replace the fuse or would be something more complex?

@classiccarmaintenance 3 ай бұрын

@TheChunckymunkey 3 ай бұрын

@@classiccarmaintenance oh, in other words there’s something wrong with car that’s going to cost a lot of money to fix. Got it. Currently having the issue with my battery dying after only sitting for a week with driving.

@classiccarmaintenance 3 ай бұрын

Not necessarily, no. It might be as simple as a loose wire, the interior, trunk or glovebox light that stays on without you noticing. If you can pinpoint where the parasitic draw is located, you can either try to fix it yourself or tell a professional where it is located, saving him time and saving you money. About your battery dying after a week, you said it was while daily driving it? If that’s the case then you might have a bad alternator. Your car uses electricity from your battery to run and operate all the electronics, and your alternator is powered by the running engine to charge the battery while driving. If your alternator doesn’t work properly the battery won’t charge and will drain even when you drive your car. We have a video on how to test your alternator with a multimeter as well so you may want to check it out, it’s a really simple test.

@TheChunckymunkey 3 ай бұрын

@@classiccarmaintenance mistake on my end, it’s not a daily driver. I have a company truck. My personal is driven 1-3 times a week sometimes less.

@classiccarmaintenance 3 ай бұрын

Our advice is to first test if the battery is still good with a battery tester, then check if the alternator still works. If both battery and alternator are OK, you want to look for a parasitic draw. We have a video on each of these subjects, so make sure to check them out, it’s easier than you might think.

@MrHavokman 3 ай бұрын

If I disconnect the negative cable the car then has no power. How do I do the simulated radio test wtihout power?

@classiccarmaintenance 3 ай бұрын

@utahenduro4808 2 ай бұрын

How did the radio turn on when the battery wasn't connected?

@classiccarmaintenance 2 ай бұрын

@bivideo7 7 ай бұрын

Read mV drop across fuses...

@KaylaHealy-f4e 6 ай бұрын

Hello I'm trying to setup my multimeter to the correct setting.on my multi meter mine doesn't have the A-~ but it has the 10A-~will that still work ?

@classiccarmaintenance 6 ай бұрын

Hi! Yes this should work just fine if your multimeter can measure milliamps in that setting. Put it on 10 amps if this is your multimeters' highest setting and see what it reads. To get a more accurate reading, if your multimeter has multiple amps settings, then select the amps setting just above the parasitic draw your multimeter is reading.

@KaylaHealy-f4e 6 ай бұрын

Thank you also when I plug the red leed into the 10A hole it doesnt get any readings. The voltage frequency hole(max 300v) gets readings with the red lead will that still work the same ?

@classiccarmaintenance 6 ай бұрын

No, you need to measure amps, not voltage. Sounds like your multimeter isn't sensitive enough to measure the parasitic draw or is malfunctioning. Even if your car doesn't have a parasitic draw, your multimeter should measure some milliamps, never a zero value.

@KaylaHealy-f4e 5 ай бұрын

Hello I bought a new multimeter with the correct settings . It.shows a 1.39 draw on the multimeter and right away the horn started going off . Am I doing something wrong ?

@classiccarmaintenance 5 ай бұрын

It's impossible to tell what's exactly going on not knowing the setup of your specific car, but chances are you set off your car alarm by disconnecting your car battery. This could in turn activate your car horn. This would also explain the 1.39 (amps?) draw your multimeter is reading.

@patrinogwaro913 Ай бұрын

And how does the radio draw power with the terminal disconnected ? Did I miss something ?

@classiccarmaintenance Ай бұрын

@stevet603 6 ай бұрын

I have a reading 0f 4.8mA (no matter what the setting on the multimeter the decimal point doesn't move?doing this) .I can't turn the ignition to accessory position to test the a draw increase as not even the dash or interior lights come on with the battery cable off, let alone the radio?

@classiccarmaintenance 6 ай бұрын

There is no need to turn your key to the accessory position to test for parasitic draw. You should test this with all electronic components and accessories turned off and wait until the computer goes into sleep mode if you have a modern car. In our video we turned the key to accessory mode with the radio on to simulate a parasitic draw for demonstrational purposes, as our car did not have electric issues.

@stevet603 6 ай бұрын

@@classiccarmaintenance Hi, new starter motor fitted. Today I tried removing all fuses one at a time with the multimeter in series on the neg cable. With car shut and locked, (apart from bonnet). After a while I got a 0.35A to 0.15A draw. Removing fuses one at a time (from all 3 fuse boxes), didn't do anything. Removing the positive feed to the alternator (from the battery terminal) didn't do anything, (did this checking for a shorted Diode causing drawback). The only way it totally disappeared was by removing the Positive connection to the engine bay fuse box; But that just made it read as zero. I don't know what else I can check now?

@classiccarmaintenance 6 ай бұрын

Hi, could you specify if you disconnected the positive cable to the fuse box at the battery terminal or at the fuse box?

@danschenck9442 24 күн бұрын

are you puttingignition key to on position

@classiccarmaintenance 23 күн бұрын

To test for parasitic draw you need to turn the key to the off-position and make sure nothing is drawing power. In our video however, because we did not have an actual parasitic draw, we simulated a parasitic draw by turning the key to the accessory position. This turns on the radio which draws power, and shows up on our multimeter as a parasitic draw.

@shimanoo11 9 ай бұрын

Do you need to lock the car first?

@classiccarmaintenance 9 ай бұрын

You don't need to lock the door. Just closing the door is fine, unless the parasitic draw is in the locking system, but that's highly unlikely.

@shimanoo11 9 ай бұрын

@@classiccarmaintenance Thank you so much!

@gegervary 5 ай бұрын

How does the radio in the car turns on if the negative lead is off? 🤔

@classiccarmaintenance 5 ай бұрын

With the multimeter forming a bridge between the negative battery terminal and the negative battery lead, there is enough current passing through the multimeters' test leads to power the radio and other small accessories. However, the amperage is limited by the capacity of the multimeter itself and its internal fuse(s).

@matsudakodo 3 ай бұрын

I'm connected as shown with a Southwire 21550T but current isn't passing through. Stumped.

@classiccarmaintenance 3 ай бұрын

If you can’t detect anything even after verifying that your multimeters’ test leads are properly connected and making good contact, the dial is switched to ⎓ DC Amps (with the dotted line under the straight line) and the DC Amps setting is switched to a range that can detect milliamps, then there might be a blown fuse inside your multimeter. You can easily screw open your multimeter and take out the fuses one by one (if there are multiple) to test them for continuity. If you can’t detect any continuity then the fuse is blown and you’ll need to replace it. If the fuses are ok, then your multimeter might be malfunctioning.

@matsudakodo 3 ай бұрын

@@classiccarmaintenance thanks, I will look into that. But I'm also thinking this meter can do DC current through the clamp only. Sounds odd, but even the manual says to use the clamp for DC current.

@citymarine7256 6 ай бұрын

How does the radio turn on when the battery is disconnected?

@classiccarmaintenance 5 ай бұрын

@XpertHeadyVids 8 ай бұрын

You said to keep doors locked all time. But you opened the door to get in to the fuse box, wouldn’t that mess up the test?

@classiccarmaintenance 8 ай бұрын

That’s a valid question, you have a good eye! If you have to keep your door open to film the testing process like we did, or because the fuse box can only be reached with the door open, you want to manually lock the door locking mechanism or tape off the door jamb light switch to prevent keeping the computer(s) awake and to shut off the interior light(s). If you manually lock the door locking mechanism with the door open, do not forget to unlock the locking mechanism before slamming the door shut though! It’s a good idea to put some tape on the door or on the door handle as a reminder. Because our ‘98 Wrangler only has a very basic ECU, it does not “lie awake” (pun intended) over an open passenger door. We just removed the only interior light bulb to prevent it drawing current.

@XpertHeadyVids 7 ай бұрын

@@classiccarmaintenanceokay got it thank you! Great video btw!

@damon-t4l Ай бұрын

Wouldn’t a draw of 2mili amps be too little?

@classiccarmaintenance Ай бұрын

2 miliamps is great, the lower the number the better.

@WheelerAutomotiveMarysville 2 ай бұрын

Everytime you remove and install a fuse, it's possible to restart the networks. Then you have to wait for the networks to sleep. This can take 45 minutes on many cars for computers to sleep. This testing process is outdated and flawed for any car built after 1996. A low amp clamp and DVOM to run parellel with fuses is the way to go.

@classiccarmaintenance 2 ай бұрын

Thanks for your input! In case the parasitic draw increases after plugging the fuse back in, you know that some part of the cars' electronics have woken up, that's absolutely right in case of some modern cars. But the principle of locating the parasitic draw stays exactly the same. Just like initially, you only look at the amp drop when removing the next fuse, yet with the new amperage reading as the benchmark. So if you pull the next fuse and the amp draw drops significantly, you know this circuit has a parasitic draw somewhere, regardless of some electronics that may have woken up by reinstalling the previous fuse.

@donmiller61 6 ай бұрын

I guess with classic cars you don't worry about wiping out the car's computer memory (for whatever it saves) by pulling off the ground cable.

@classiccarmaintenance 6 ай бұрын

You’re absolutely right, disconnecting the car battery is not an issue with old school cars that don’t have advanced electronics or accessories. However, If you have a modern car with electronics and/or accessories that need continuous power supply to not lose data and settings, you need to hook them up to an external power source to power them before disconnecting the battery. Always first check your car's owners manual and your car accessories' owners manuals for instructions. However, it’s important to know that if you use an external power source, you won’t be able to tell if the parasitic draw comes from any of these hooked up accessories or electronics.

@donmiller61 6 ай бұрын

@@classiccarmaintenance Lately with my "modern car" ('07 Acura MDX) I had a parasitic draw (well-known to dealers and many, many owners) and I became an armchair KZbin "expert" on the issues of draw and memory saving. With the investment of a $40 Digital Clamp Meter (that also has other Multimeter functions and probes) here's what seems to be the best "modern" approach IMHO (mostly from a former Acura mechanic): 1) Put the clamp meter around the ground cable to measure DC amps. No battery cable disconnection. No outside power e.g. 9V battery, another 12v battery, or jump starter, needed to maintain memory components or to hide a parasitic draw. 2) Test compatible fuses (conductive access to both poles) with a multimeter in a systematic manner without pulling the fuses to test voltage drop. If a wiring diagram is available that's even better, or just common sense from labels on the fuse box works, e.g. if the radio or wipers work - don't bother testing their fuses.

@agde0968 2 ай бұрын

After 6 months of flat batteries , my draw was minimal most videos say it can be ignored, not for me very small car battery aftermarket hardwire. Of Nextcam dashcamwas the culprit Beware!!!😿🥵🤐

@I.Live4oldcars.prospecting 25 күн бұрын

I did this test on my car. But I'm confused. Can you help please? My multimeter shows 0.066 . Sometimes goes upto 0.070 .

@classiccarmaintenance 25 күн бұрын

Your measurement of 0.070 (70 milliamps) is above the accepted 0.050 (50 milliamps), which means you have a small parasitic draw. You now need to locate the fuse box and start pulling the fuses one by one to see on which fuse your parasitic draw is located, as shown in our video. Once you know on which fuse the parasitic draw is located, by further elimination you can now determine which wiring or electronics that are powered by this fuse is (are) causing the parasitic draw.

@RideWithYaH Ай бұрын

You opened the door, to find the draw and didnt mention how it would also be drawing current at that point.

@classiccarmaintenance Ай бұрын

Well spotted! Like we said you have to keep the doors closed to prevent this from happening. However, if you have to keep your door open to film the testing process like we did, or because the fuse box can only be reached with the door open, you want to manually lock the door locking mechanism or tape off the door jamb light switch to prevent keeping the computer(s) awake and to shut off the interior light(s). If you manually lock the door locking mechanism with the door open, do not forget to unlock the locking mechanism before slamming the door shut though! It’s a good idea to put some tape on the door or on the door handle as a reminder. Because our ‘98 Wrangler only has a very basic ECU, it does not “lie awake” (pun intended) over an open passenger door. We just removed the only interior light bulb to prevent it drawing current.