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05 Avalanche parasitic drain on battery

mwr1mab

New Member
Joined
Jun 26, 2018
Messages
1
Have had my 05 Avalanche to two shops.  First one could not find the source of the parasitic drain.  The battery will drain over night or sooner.  Second shop said it is the ECM.  They told me that it needs replaced and only a dealer can reset it.  Is that true.
 
Sounds like lazy shops that don't want to tell you they will charge you $300 to find your issue.

Go to Harbor Freight tools and get one of their $10 volt OHM meters and use the amperage feature.

Disconnect your negative battery cable and place the VOM so the Negative is connected to the battery and the positive is connected to the negative cable. Also note you will need the black wire in the COM port and the red wire in the top port and the selector dial on DC AMP.

Just went through this with my truck...

You should see a value on your display. On my truck when nothing is going on it is like .03 amp. But you have to wait a few seconds for it to drop because when you connect with key off you will add power to the modules and they have to go silent and shut down. Which could take as long as 5 minutes.

Then once you have the voltage set you start pulling fuses in the under hood fuse box until the amperage drops off. Once that happens you can then start tracing the circuit until you find the issue.

In mine the 60 amp fuse that goes to the under dash fuse panel next to the parking brake under a black cover was showing a draw. I had 5.4 amp draw on mine.

I was able to trace it down to the largest Orange wire from the box which appears to go to the passenger seat. I moved the passenger seat forward to pull the harness to check and the draw went away. So I don't believe I resolved mine but it hasn't come back.

If your not any good with a VOM you might want to find a buddy that is that can help you. Took me about an hour to trace down the circuit with about half that searching what the fuse name meant, where it was and going from there. As a side benefit I know where the brake controller wire now plugs in.




 
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