EASY - Diagnose/Fix PARASITIC BATTERY DRAW 

Had a coworker that relaced the battery, alternator and cables. After a week of sitting idle the battery would be dead. He got so mad he sold it to me for $500. This was in the early 80s and the car was in excellent shape. I got the car home and parked it in the driveway. That night I looked outside from the upstairs window and thought I saw a little glow from the car. It was the glove compartment light. Removed the bulb and drove the car to work for 4 years with no problems. Your videos are very helpful. Thank You.

I'm a retired mechanic , with a draw on my battery , just wanted to say you filmed an excellent video , to the point , easy to understand , Great job .

I've watched several of these parasitic draw videos and this one was the easiest to understand by far. Thank you!

Thank you for explaining in detail how to hook up the multimeter in series with the battery. I've watched many parasitic-drain videos and none of them showed how to hook the meter up to the battery to start collecting numbers. This is the most important step in diagnosing parasitic drain and if someone is making a video for instruction you would think they would do what you did...but the brain locks up for some people and not everybody makes a good teacher. You're a great teacher.

Great video, working through this issue on a friend’s car. 0.25 is actually 250mA (not 25mA) :-(

As soon as you said glove box I looked over and saw a light on for no reason! God is good, thank you bro.

Great video! Perfect presentation, really clear instructions and well narrated! Thanks!

Thank You D and E for the informative video. I appreciate it when good people explain technical problems in a way “commoners” ( like myself ) can easily understand. Have A Good Day! And I appreciate the comedy relief inside the video. 😁👍🏼😎

One of the factual, informative videos I have ever seen on any subject on RU-vid... Great Job ❗

You gotta be kidding me on the timing of this video!. We have a 99 Grand with the very same problem. Just found out this morning. You guys ROCK!!! Much love, brothers...

Best video on this topic. I am in the category of buying a car when I did not know fully what the prior owner installed. Found a draw that was making my battery go to 4.5v overnight. Found aux cable for radio behind the radio in a aux box. Removed that 3 weeks ago and now still having draw. Remote starter needs to be investigated. Radio fuse was the amp drop but could have other components on it. Just this week it is drawing again. Even has kill switch I/O on underside of dash. I have to trace this circuit as you say. I hope to get this fixed and do biz with you guys. Thanks.

This may be one of the most useful videos I've ever seen on RU-vid. That it's using the exact same Jeep I'm working on is an even better coincidence. Thanks!

Great video, exactly what I wanted and clearly explained, Thanks.

One of the major causes of parasitic draw is a faulty relay, that is one of the first thing I'd check, the cause the draw by being 'frozen' in the closed position when they should be in the open position when they car is turned off.

FANTASTIC, Never used a meter before in my life. Just bought one and found fault already. Very well explained, easy to follow. Thank you so much. I appreciate it. Definately subscribed

Your video is great and easy to understand. Good job. Very helpful.

I applaud you for sharing what you know with the youtube community. @404 your meter was actually measuring 250 mA (0.25A), not 25 mA. You are correct that ~50 mA is a typical and acceptable parasitic draw. If you had waited a minute or 2 after connecting the leads in series, that 250mA would likely have dropped to the expected 50mA draw. Additionally, you were completely correct when you say it takes a while (some vehicles are quicker than others) for the current draw to reach steady state and stabilize. Most vehicles take

Good video dude, so many are out there giving incorrect or incomplete advise, you did great, clearly not your first rodeo.

Thank you, finally a video that is step by step, understandable explained and a meter I can buy cheap. I'm going to try and find my Jeep's parasitic draw myself before I take it to the shop.

You HAVE NO IDEA HOW THANKFUL AND HAPPY AM THAT CAME ACROSS YOU AND YOUR CHANNEL!!!! THAAAANK YOU!!

Excellent video. Parasitic draw clearly explained.

That was outstanding Brothers weather information especially for somebody that's got an old beat up vehicle like I have

Excellent video. Helped me solve the draw on my battery for a 70 skylark. Bad door switch.

Great video, thanks for keeping it simple and informative

i have seen numerous videos on this subject, your video has to be the best explained video so far, good work.

Excellent presentation, thanks very much.....

This is the best video i have seen for along time in its presentation. it explains everything in layman language and assumes the person watching has a limited knowledge of the subject. No terms are used that leaves the viewer asking "what the hell does that mean". You also explains how to use the multi meter .clearly. You should go into teaching as you keep the lesson at the student level without going over their heads. Well done.

Thank you for this video. Awesome and convenient that i have the same exact multimeter!

I've stumbled through this procedure add hock,, You described what it took me a dozen screw ups to eventually find the problem. Great explanation.

Best video by far on parasitic draw. Good pacing and explained well. Thanks!

Well. Watched your vid, grabbed my meter and connected to the battery. My old 1981 2.8 injection only has 7 fuses. Got to the 7th and there it is. The 57 milliamp draw stopped when I pulled it. It was the new radio I fitted, don't need the clock so I pulled the power from it while I was there. Off to order an isolator switch now as the cars just for shows etc. Great teacher 👍👍

Wow The best video I've seen on parasitic draw and I wasn't even looking for it. I have a truck I was trying to use a multimeter on and I knew it had a drain. But now I know it's from the after market double din and led lights he put in.

Great video! Exactly what I needed- thanks bro

I won that thing. 😎 Thanks again Doug and Eric 😘

Good video. Clear and accurate explanation

Unplugging fuses and plugging them back in can wake up the car again. The best way to pinpoint it with just a DVOM is to do a voltage drop across each fuse, with the meter reading mV. Power Probe has a chart that shows what mV reading equates to what mA draw, depending on the fuse type and size. Your voltage drop at each fuse should be 0mV. If you have a voltage drop across the fuse, it’s because the circuit is still active. Once you’ve pinpointed the fuse that’s the culprit, you then have to figure out what that fuse powers. Let’s say there are 3 components that are powered by the fuse that has a voltage drop reading across the poles. Don’t take that fuse out, but put your meter in series to read out the mA draw at the battery, and disconnect the given components one at a time until the draw goes away. When it does, you know what was causing your issue.

Tips: Parasitic draw problems can be very diverse, so it is hard to say which testing method is better than another. It really depends on the symptoms and the complexity of the vehicle and its electrical design. 1) Start with the battery charged, this is good advice if you have time. To fully charge a battery could take up to 12 hours or more, and batteries exposed to parasitic draw tend to arrive at the shop practically dead. I think what is important is that the battery is not dead. Perhaps 75% SOC may be more realistic to start testing. 2) The vehicle must go asleep and make sure to put into a state where the customer leaves it during the draw, like locking the doors for example. If it is parked in a garage maybe the customer does not lock the doors. Keep all test leads and hands away from any electric cooling fans. If there is a hood switch for a light or module this will have to be disabled off. Same with a trunk light and or switch if you want to troubleshoot fuse panels in the trunk. 3) Like in the video, if you remove the BAT NEG lug you will reset the system. Parasitic draw in newer vehicles may require a special sequence of operation to show itself. If you interrupt power the problem could go away until the customer recreates it. That is, recreates a special sequence of operation. So, if you want to introduce an Ammeter or a shunt you have to do it without interrupting power. Parasitic draw current profiles may be complex, meaning periodic ON/OFF or something more complex. So the current meter reading may be dynamic in nature or perhaps periodic. 4) I use a clamp meter first, if I can fit the jaws around around one of the battery cables, like the B&K 316, which has a resolution down to 1mA DC, and also measures DC Volts. If you use a clamp meter you can easily go key on. I would have to say that the clamp meter is more useful in this case than a DMM with a 10Amp current range. There is a danger when going key on, obviously the vehicle will wake up and draw a lot of current, and might even turn on a large load like a cooling fan or pump motor. These higher currents could overcurrent an inserted DMM amperage limit, which may blow a fuse. What if the battery is in the trunk? Well if you have a wiring diagram the main power feeds usually come to underhood fuse boxes before going to other interior fuse panels. Usually like two. If you can get to these wires you can use a clamp meter to measure the current. 5) The real issue with complex parasitic draw failures is they can take a long time to diagnose. Maybe even over an hour, after the vehicle has gone to sleep, depending on the vehicle and what has failed. If you know what you are doing and using a clamp meter you can use a DC power supply to put the vehicle on "life support" while you are troubleshooting. Just like using a voltage regulated power supply during Flash Reprogramming which also can take a long time, meaning don't rely on the battery to supply power during the testing. If power is interrupted or inadequate the problem may reset. For parasitic draw I would recommend an old style 15VDC 20Amp voltage regulated linear, current limited, bench power supply. The output is very low noise as compared to a switching power supply. Match battery voltage, connect, and then increase the voltage so that the battery is taking a very small draw (charge). Now you can keep a constant voltage while you are doing the testing and slow charge the battery. If you have to go key on to key off to diagnose the parasitic draw problem remember a load may be actuated. The battery can usually supply the starting surge for a motor and then the supply will take over.

Great video been searching my ZJ for a draw, still doing it I guess I’ll find it sometime. Thanks Mike

Excellent video man! I’m terrible with electrical especially testing and you made it very straight forward and easy to understand in this video. Thanks!

well done , coherant and all relevant. thank you.

My problem too,thank you.

Excellent explanation, i don't think anybody else has a video about this kind of problems, but many cars have it, i think as you said it, most of the time is by incorrectly installing extra after market thing to the car such as stereo, lights .

thanks so much this made it easier to understand and set the meter up correctly

Thank you for this excellent video!

thank you very much this saved me a good amount of money garages in my area a very expensive.

Great video really helpful!

Best video on the subject. Though I don't have a jeep but a misfit 05 Mustang with 2 different batteries now that drain quite often.

Ty so much it was driving me crazy I was skeptical at first but boom it's done thanks again

Well done! Very helpful.

excellent explanation. many thanks sir

Excellent video man, explained in a simple, straight forward manner. Step by Step. That's how you do a how-to!

Great detailed video ! Thanks

Just to mention - around 4:00 time mark the current draw measured is not 25 mA, but 250 mA, which is way more than it should be.

The Best Video Ever...Thank you Sir.

I like the detail in your explanation.

This is such a great video Doug. It's gonna help alot of people. Awesome job with the giveaway 👍. BTW I'm so glad you said to disconnect the hood light 🤣 that one gets me every time! Haha

Very good vid...thanks.

Good info and understanding

Thank you! Excellent video!

simplest way to do this test! very good mate thanks!

Well explained, Thanks

Best explanation I've seen. To the point, thank you.

Those damn water pump circuits, they are always a problem. Love the videos, keep them coming

Great video, thanks for sharing. Cheers

Very good methodology of fault finding

Excellent helpful video. Thanx .

Thank you so much with this information

Nice job....guick, clear and understandable. Thanks 😊

Best video on youtube thanks great video

Good video here. Thank you sir

Watching your video...now I get it. Thanks.

Thanks for showing this. Wow, my Mom's 2010 Grand Marquis is drawing 3.42 amps! Her car sat for 3 weeks because she had fallen and broken three ribs. When she was well enough to drive, it was dead. I put a new battery in it. Two days later, it was dead. So, I knew something was draining it down. I just checked it like the video says for a draw - it's reading 3.42 amps - and now I have to do the elimination check.

U need 2 latch your doors to. Opening , closing , and leaving your doors, hood and truck open will continue to draw current and give you a misread. So open your doors and push the door latch to the closed position and THEN leave your car to set for an hour. If your not sure there closed check your dash for any lights or warnings.

Thanks for making this video

Great video. Thank you

Great info , to the point . Thanks

Dont forget to check the lighted mirror on the passenger / driver sunshade. Their on/off switch is cheap plastic which the sun bakes and then the light stays on constantly

Awesome video, well done , thank you I’m sure it will help lots of people out there

nice and clear

Dude!!! What a great tip man !!! Thank you thank you !!! Wow !!!I learned a lot !!!

thanks good explaining

Thanks for sharing

Nice and concise!!!

you can add a fuse holder in line with your lead and install a 7 amp fuse to protect your meter from getting more than 10 amps!

Your video was better than any other video I have watched. I like the way you showed the multimeter and showed exactly what you were setting the dial to.

Very helpful thank you

Great information.

I think you just solved my problem, theres a remote start i dont have the fob for thats probably causing my draw thankyou awesome video

Thanks a lot - nice one!

Great video. We've found a common source of parasitic draw is shorts due to corrosion in connectors.

Brilliant video

Thank you so much

Thanks for the useful vid. I think a small active sub might be draining battery. I'm sure I fitted it correctly, but this will allow me to check.

Great video!

great video a 5 amp max multimeter works to do this job

Thumbs up for having the same MM as I have.

Am I the only one that reads through the comments to see if anyone has already said what I wanted? I'm sure he was made aware by the 1st comment. 50 more is unnecessary. Or is it more about saying "look at me, I'm smart"? Good video dude. I knew what you meant when you misspoke.

Thank you kindly

Great job

excellent!