How To Test Parasitic Draw on a Car Battery

[@Ideal-Setup]

You just taught me so much in so little! Great video. Straight to the point and very detailed as always. Those multimeters are very useful. I need to snag me one for sure.

[@StevesGarage]

Quick and informative was my goal! Multimeters are great to have around. You might not need one often, but when you do it's the perfect tool.

[@zachlenning2653]

Had an intermittent drain on a 2000 Bravada few years back. Finally found it. The vanity light switch was failing and the light for the vanity mirror on the sun visor would, sometimes, come on. Couldn’t see it because the flap was closed. Took forever to find.

[@StevesGarage]

It seems like every story of a battery drain is different. I haven't had a vanity mirror switch like that go, but I have had problems with a poorly wired radio and a door switch. I've also seen someones phone holder contacting the eject button on the radio and that was causing a drain.

[@Snowdog216]

Good info thanks. Always look at the vanity mirror lights first. In a dark area with the car off, key out, you should be able to see some light around the edges. Or could try to use a temperature reader. Handheld, you can get them at harbor freight. If the vehicle has been sitting for a few hours the visor area should be same temp as everything else around it. The old GM switches are just a little plunger like, the size of a pencil lead. If it is the vanity light, I would just pull the bulb out.

[@willquick5090]

Think that’s what I found on my 2000 blazer PO taped it took forever thought it was the aftermarket radio

[@onehmong9368]

Nice

[@abhijeetkumbhar-y2z]

drive car for 50km yesterday and today morning, car stopped to start.. never before i have this issue, car is making tuk tuk noise and and i cab see fluctuations in all the lights, plus battery light came on.. what can be the issue? also car’s battery is under warranty..

[@StevesGarage]

I'd look at the battery or alternator before looking at a draw issue.

[@abhijeetkumbhar-y2z]

@ thank you for the reply, as i diagnosed.. one of the cell in battery was dead. and it was under warranty.

[@StevesGarage]

@@abhijeetkumbhar-y2z I've replaced my fair share of batteries under warranty. Glad you got it figured out!

[@mfitzpatrick1617]

Great video but hard to see how you connect then leads. Are both black and red connected to negative post?

[@StevesGarage]

One goes to the negative post on the battery, the other to the negative battery cable.

[@buggz3389]

I have a 2002 Nissan frontier was reading 0.40. I replaced the ignition switch now it’s at 0.07 for a draw. Iv checked every fuse, relay, battery and alternator are good.

[@StevesGarage]

Interesting. Is it a common problem with those trucks so you just went for it, or did you diagnose it to be the ignition switch?

[@buggz3389]

@ I went through testing and pulling fuses, the ignition switch dropped it to 0.07

[@StevesGarage]

@@buggz3389 Nice diag! Glad you figured it out and got your truck back in tip top shape.

[@BrentDuncan-t4s]

Hook up meter shows 2.24 but starts to go down to 0, what's wrong can't check for draw.

[@StevesGarage]

That sounds like a connection issue to me. A reading of zero is pointing to a problem with your meter or wherever you're hooking the probes up to.

[@chrismcdonald6481]

Got a 07 ranger 4.0 . When its freezing outside its like my batteries dead but i got 12.4 volts. Alternator charging 14.3 battery is 6 months old BUT only 590 cold cranking amps. My 4 cylinder pt cruiser was 625CCA. ITS FINALLY warming up to -2 tomorrow so try the parasitic draw testing, but does the 590 CCA seem low for a 6 cylinder? Any help would be appreciated. Before i freeze my butt off. Thanks( currently on charge going to see if drops overnight)

[@StevesGarage]

I would think 590 should be enough, and the 625 on the PT Cruiser almost sounds like overkill. Sounds like your battery is healthy. Did you check all the connections? I wouldn't rule out a faulty battery either, I've had that happen. If all else fails I'd bring it back and ask them to test and possibly replace it.

[@chrismcdonald6481]

@StevesGarage I ended up taking it to local battery dealer who did a free test and it is the battery. Even after charging it fully overnight and reconnecting brand new terminals it just barely started at -2° just waiting for a new shipment of batteries to come in. I was told in May by previous owner it was a new battery. Guess he meant new used battery. Thanks for your reply, greatly appreciated

[@StevesGarage]

@@chrismcdonald6481 Glad you got it sorted out! It sucks it wasn't a new battery, can't trust anyone these days. But getting it solved is good, especially in the winter!

[@TomKnox-f1k]

Dont forget to check water levels in battery. If its low the battery may not be able to sustain even a common 20mA draw.

[@StevesGarage]

Do they sell serviceable batteries anymore? I haven't seen one in years.

[@garaiselvis]

My battery starts to die off in cold autumn before the winter. 2 days without driveing and i get 2 poor cranks and thats it. Battery is almoust 2years only and in summer no problem. I got this promblem in first winter with new one. Will try the multimeter again. Last year i checked with no problems. Dont know, maybe bad battery with low water level

[@StevesGarage]

​@@garaiselvis I don't know of newer batteries that are serviceable. As far as I know they're all sealed. If it's not holding a charge and you bought it 2 years ago you should be able to get a new one prorated for the amount of time you've had yours.

[@erichernandez9751]

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 then turns to 10mA when a relay clicks after 20 mins. Is this normal? I hope I get noticed..

[@StevesGarage]

Is it an aftermarket alarm system? I'm not familiar with Toyota in particular, but I know my XC90 has systems running before it 'goes to sleep'. It's doing things like scanning for the key, closing the hvac vents, etc. If the relay is consistently clicking off after 20 minutes that sounds like normal or expected behavior for the car.

[@erichernandez9751]

@StevesGarage No its the stock alarm. I'm just wondering why the dome fuse is drawing that amount of current for 20 mins. Isn't that odd?

[@StevesGarage]

@@erichernandez9751 You'd have to look into your car specifically. That circuit could be running a system that stays on for 20 minutes before going to sleep. I'd be more concerned if it ran indefinitely than shutting off after a period of time.

[@erichernandez9751]

@StevesGarage Thanks for the input. I'm looking for a circuit diagram of the dome fuse now so I can check what is hooked on to it but I had no luck finding it online.

[@StevesGarage]

@@erichernandez9751 If there are repair manuals available they typically have a wiring diagram!

[@shinigaminova728]

What if it fluctuates between 0.05 and 0.06?

[@StevesGarage]

I would say it's probably fine seeing as there is a margin of error on multimeters. Do you think you have a parasitic draw?

[@shinigaminova728]

@StevesGarage I believe so the battery has dropped to 10v over night for the last 2 weeks.

[@StevesGarage]

@@shinigaminova728 Oh wow, definitely something going on. Since the parasitic draw is coming back close to normal, is your alternator properly charging? How old and what health is your battery in?

[@Progressive.G]

Would it be a good idea to replace the fuse or just permanently keep it empty?

[@StevesGarage]

The fuse isn't the issue, it just disconnects whatever is. For example if you isolate an aftermarket radio as the source of the draw, there's most likely an issue with the wiring that is causing the radio to draw power when the key is off. Pulling the fuse will stop power from going to the radio entirely. It technically solves your draw issue, but you also can't use your radio without the fuse in place. You'll want to diagnose the issue causing the draw.

[@aakudev]

Thanks, my multimeter shows 11.0 draw, don't know what just happened, will check my radio, it just makes a pop sound every time I turn it on😢

[@StevesGarage]

The radio makes a pop sound, or the car does?

[@aakudev]

@@StevesGarage Yepp, I hear a pop sound from the front tweeters when turning the radio on.

[@StevesGarage]

@@aakudev Do you have aftermarket speakers or a head unit? It sounds like you need a crossover.

[@aakudev]

@@StevesGarage Yes, I have a Pioneer double din since almost 12 years in my Civic. I also have Infinity components with crossovers. Everything was fine and this pop sound recently started, I checked the wiring too. Do you think it could be that the head unit is too old and can have issues?

[@StevesGarage]

@@aakudev It's been a while since I've done anything with car audio so it's hard for me to give you specific advice on that. It's possible you have a bad ground. You could also check the resistance of the speaker.

[@evananthony2337]

Anyone have 2016 dodge dart parasitic drain?

[@StevesGarage]

Unfortunately my only experience with a Dart was driving one as a rental. Do you have any aftermarket electrical items on the car?

[@Snowdog216]

Good info, thanks. I would not suggest a BM 15D multimeter. I think they are sold under different names. Just a pain in the azzz all around. You have to press a button to toggle to the setting you need. The instructions are worthless, and to change the fuse you have to take off the plastic protective cover and need to use two paint can openers, look like bottle openers to pry it off. And the fuse was dead as you mentioned. Which is probably not the multimeter fault, but mine. And they do not list the size of fuse in the instructions. ugh.

[@StevesGarage]

There are a ton of multimeters out there, and some are definitely junk! I got mine from Home Depot and it's worked fine for me. There are certainly nicer ones out there, but I'm not using it every day so it's not like I need a high quality one. I did have trouble finding the correct fuses for mine as well, but they were at least listed so I knew what to look for.

[@Chackers-m4s]

Thank you!

[@StevesGarage]

You got it!

[@football-qk8bq]

Mine is at 0.00 what can I do now I don't understand

[@StevesGarage]

Check your connection or your multimeter. You could be on the wrong setting, wrong ports, or have a blown fuse.

[@football-qk8bq]

@@StevesGarage a blown fuse in the multi meter or vehicle?

[@StevesGarage]

@@football-qk8bq Your multimeter. If there was a blown fuse in your car something wouldn't have power.

[@football-qk8bq]

@StevesGarage ok thank you

[@StevesGarage]

@@football-qk8bq You're welcome, good luck with it!

[@Fingamyaz]

i did a draw test and i get 40ma with the remote starter. (new battery in 2022). 2-3 days not driving the car. the batter would get drain. i removed power to the remote starter and it draws only 20ma. the car would sit for 3-4 weeks and still be able to start fine. so you saying under 50ma is okay.. makes me confuse af.

[@StevesGarage]

Have you checked your alternator to make sure it's properly charging the battery? If it were me I'd also look over the wiring for the remote start system. Start by checking your grounds. I have a remote start system on my Volvo and it doesn't have that high of a draw.

[@charlessanders1342]

I have had my battery unhooked for 30 plus minutes so everything could loose power and tested it gauge jumps way up not sure what the draw could be I have a basic needled gauge which nobody on KZbin has not even sure where to set it I have tried multiple positions and gauge jumps up but it's prob normal for a POS DODGE.

[@StevesGarage]

If you're disconnecting the battery and re-connecting it with the multimeter you'll need to wait for the car to sleep again. If you wire in the multimeter before disconnecting it and then leave the multimeter as the connection it should maintain the 'sleep'.

[@elementn4107]

What about the memory saver before disconnecting the battery

[@StevesGarage]

I've never used one. Many more modern cars can retain some level of information even when disconnecting the battery. My 2000 Volvo will remember radio presets and seat memory settings.

[@elementn4107]

@@StevesGarage my professor told me to always use a memory saver especially on newer cars

[@StevesGarage]

@@elementn4107 Then go for it I guess? I've never had an issue with a car not running properly after a break in power so besides retaining the clock, trip, and radio presets I'm not sure why you'd need it.

[@bigjohncountry3453]

Are you an auctioneer?

[@StevesGarage]

Aspiring to be one.

[@TomKnox-f1k]

Use distilled water or water made for the battery only. Never straight water.

[@StevesGarage]

Correct! As long as it's actually serviceable. You don't want to go cracking open a battery that isn't meant to be.

[@jester-gq9jq]

👍👍👍👍👍👍👍

[@StevesGarage]

👍 Glad you liked it!

[@RacecarsAndRicefish]

"anything that's not stock-- check those things first" 😭

[@RacecarsAndRicefish]

is 52mA bad?

[@StevesGarage]

@@RacecarsAndRicefish Just took a look at your channel to scope out the car... sorry to be the bearer of bad news 😅 52mA certainly isn't terrible, but I'd look into it. Maybe you just have a bad ground or something wired a little funky.

[@RacecarsAndRicefish]

@@StevesGarage I've gotten it narrowed done to one fuse and it looks like there's only a couple things that run off it-- I'll have it solved in no time 😎 thx for this video

[@StevesGarage]

@@RacecarsAndRicefish Woo! Narrowing it down is great! Glad the video helped.

[@RacecarsAndRicefish]

@@StevesGarage Im finding 48 - 52 mA, then I disconnect my 4 aftermarket gauges and it drops to 20.5mA, then I additionally disconnect my radio and I see 19.3mA. So one or multiple of my aftermarket gauges are the main issue. I might just have them run entirely from switched power? they'll forget their most recent color but that's fine lol

[@onehmong9368]

Too fast slow down Jack

[@StevesGarage]

Thanks for the feedback. Anything I can help you with?

[@onehmong9368]

@StevesGarage noobs like myself can't catch up but will try this week. My brand new 2024 Toyota Grand highlander xle hybrid has been draining my 12v battery. I can only imagine that it's communicating with Toyota while parking in the garage.

[@StevesGarage]

@@onehmong9368 That new I'd probably just bring it into the dealer. There's no reason it should be draining the battery even if it's connecting to the internet for updates.

[@herrprepper2070]

You talk too fast.

[@StevesGarage]

Noted.