Chevy cobalt battery drain

[KYMISTWALKER]

I have a 2008 Chevy cobalt that’s draining the battery and I can’t figure out what’s going on. We’ve pulled fuses, we’ve checked about all the wires we know. Can anybody help?

 

[mk378]

Disconnect the battery while parked. If it still drains, the battery itself is bad.

Or it's not getting charged up while running. To diagnose "battery drain" implies that you already checked that.

 

[wtd]

You have a parasitic draw. Have you used an ammeter inline to one of your battery cables to see how much draw you have and have you checked voltage across each fuse in the engine compartment and any fuses that may be inside the car?

There is a specific procedure to use to find parasitic draws and you have not described the procedure you used other than pulling fuses.

 

[KYMISTWALKER]

So you’re saying I need to put a multimeter volt meter, and then pull my fuse and see if it goes down

 

[wtd]

So you’re saying I need to put a multimeter volt meter, and then pull my fuse and see if it goes down

I'm saying that you have to put your multimeter in series with one of your battery cables to measure what your amp draw is. For example, you unhook your negative battery cable. You attach the red cable of your multimeter to the end of the cable that you just disconnected. You then hook the black lead of your multimeter to the negative battery post. You put your red multimeter lead into the AMP port of your multimeter and then select AMPs DC on your multimeter. A normal amp draw is 50 mA or less.

The best way to proceed from here is to have a second multimeter set to volts DC and read voltage across each fuse. The reading should be 0. If you have a fuse that shows voltage, that can be all of your draw or part of it. You then pull the fuse and see if the multimeter that is hooked in series to your battery cable is showing less of a reading or goes down to a normal reading. You then have to figure out what all is on that circuit that the fuse powers up. You then will put the fuse back in and start unplugging each component that is on that circuit until your draw goes down to normal. The component that you unplug that makes the draw go to normal is your problem. If you don't have a second meter to test the fuses with, you will just have to pull fuses one by one until you see the draw go to normal on your meter.

You also have to let the car go to sleep before starting the testing and after you install the multimeter in series which can vary depending on the vehicle. It can be up to an hour on some vehicles. On your car it shouldn't take long. You need to have the doors open and the latches tripped closed so the interior lights are not on in case you have to test any fuse panels inside the car. Also, pulling fuses can wake the car up in some cases so just be aware of that. Some parasitic draws can be hard to find and very time consuming as well.

 

[Patrick0525]

https://a.co/d/ffYmlJW
Amp hound


I just found this on AliExpress: $121.12 | WINAPEX DC AC 0.1mA High Precision Clamp Meter True RMS Digital Multimeter with Current Leakage Detect Home Appliance Tools
https://a.aliexpress.com/_mteG8t9

 

[Patrick0525]

My parasitic current test.

 

[The_Eric]

Does it have an aftermarket remote start or security system? 90% of the vehicles that I see with this problem have one installed.

 

[KYMISTWALKER]

It has a battery in the trunk, which is very odd on the Chevy cobalt and a high-end pioneer stereo. The stereo had two blown fuses and we were replaced those and then we even run it without the fuses and it still had a draw.

 

[pcoxe]

My 2010 Equinox had a failed OnStar module that drained the battery. Pulled the CIM fuse to deactivate the module.