I already pulled my on star fuse like 3 years ago so I know it's not that. Well today my battery is completely dead again. I'm going to get it charged again and start disconnecting my accessories 1 by 1 and test and see if I can figure out what's draining it. My god this is beyond frustrating.

 

Plenty of vids on YT to show you how to perform a parasitic drain. All you need is a multimeter.

 

Thank you... I will try this tomorrow

 

Connected the multimeter to the battery like in that YouTube video, it is consistently drawing .5. Checked every fuse with another multimeter and all of them said 0.0. I pulled all the fuses to my off-road lights and will see if that makes any difference with it dying, even though checking them they said 0.0. I even checked all the fuses inside the drivers door, and nothing, all reporting 0. I verified the alternator is working as well after starting it with the multimeter. I am at a total loss here. Any other ideas ?

 

What's the battery resting voltage????

 

do you have any features that don't work maybe a bad module drawing current?
I know our GM clusters can have issues where they do not go to sleep properly in a pre determined time. you can try disconnecting it while measuring the battery current and see if the .5 amp draw disappears.
another thing that can cause the issue is aftermarket car radios (red keyed 12v and yellow being constant 12v) and amps if improperly wired (usually a blue wire). as an example if they wired the amp remote to constant 12 volts or the amp remote circuit in the amp is defective it might stay on.

 

it was at 12.5

 

I've had the same aftermarket radio in for 2-3 years and everything seems to be working ok. Only other things with it is the wiring harness and the steering wheel module but all of it is working. Could the steering wheel module be drawing power somehow if it went defective ? I thought I'd see that when testing the radio fuse though. I have rear headrest dvd screens that are wired into the rear cigarette lighters but I installed a switch to shut their power off. So this is really perplexing.

 

Disconnect battery terminals overnight and recheck battery resting voltage before reconnecting terminals. Should not change!

.05ampdrawmax

 

it depends on how well they installed the steering button interface. maybe it is wired to constant 12v or shorted internally ? the cigarette lighter sockets are wired to 12v constant.