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Parasitic Battery Drain

T

Tango Mike

New Member
Joined
Jun 8, 2013
Messages
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2003 Z71 having trouble holding a charge over a few days of sitting. With a strong battery showing full charge, multi-tester in series with the negative cable reads 2.5 to 3.0 amps. Pulled the first under hood fuze to begin searching for the source, got a drop to .11 amps. Thinking no way did I find the culprit on the first try, plugged the fuze back in and read the same .11 amps. Disconnected and re-connected the multi-tester, again read 2.5 to 3.0 amps. Nothing I've read online indicates what might be going on. A neighbor suggested that bad relays can be the cause, but I haven't tried that yet. Any ideas would be appreciated. Thanks. Tosh
 
did you unplug any more fuses?
 
ygmn said:
did you unplug any more fuses?
Click to expand...

Haven't yet, unsure of why the setup reacted the way it did, and somewhat concerned that I might cause something worse in the process of stumbling around.
 
what was fuse? could have been the first
 
ygmn said:
what was fuse? could have been the first
Click to expand...

Agreed, but videos about how to do this show that when the fuse in the problem circuit is reinstalled, the amps once again indicate a parasitic draw. Since that didn't happen, how can I trust the test as valid?
 
Tango Mike said:
Agreed, but videos about how to do this show that when the fuse in the problem circuit is reinstalled, the amps once again indicate a parasitic draw. Since that didn't happen, how can I trust the test as valid?
Click to expand...
Quite possible that the device that was unplugged drained whatever power it had and then finished "shutting off". Hence the "no draw" issue once you reinserted the fuse.
 
Like a radio or amp or some computer in a loop
 
My Avalanche had issues with the ignition control switch acted crazy alot. Worst thing was I could take key all the way out ignition and engine would stay running until I opened driver side door, scary first few times happened.
I believe it could be draining your battery if leaving the stereo &navigation system running? May be worth checking not expensive part and took me about an hour & 30 minutes start to finish.
YouTube videos helped me complete job.

 
When you first connect the battery through the meter, there is a normal time period of a few minutes where you have a 2-3 A draw before the PCM and other sytems go to sleep.  Then the draw goes down significantly.  I just went through this before replacing the battery on my 04 Avalanche.  110 mA is a little less than mine (180 mA).  Avalanches need a good battery to keep up with the normal draw when sitting over time.

Every time you disconnect and reconnect the meter you will have 2-3A.  Pulling a fuse, no.  This is what you observed, correct?
 
You may be waking up the GM-Lan Can Bus.  Make sure the key is out of the ignition, all interior and external lights are off and the doors are shut.  Hook up your meter and wait at least two minutes for the Can Bus network to turn everything off. 
 
I was having the same problem with my 03 Z71 Avalanche. Every time my Avalanche would sit for 3 days or more the battery would be dead. Tested Alt. & battery , they were fine. Did some reading and watched some videos. Come to find out my instrument cluster was causing a parasitic draw on my battery. Shipped it out for repair because a replacement is very costly. Installed cluster back in and everything is working great. I also paid a little extra for them to upgrade the lights to LEDs and I really like how bright it is now. $129 + shipping to them was more affordable than a replacement for me. Not to mention they send it back with a lifetime warranty. Hope this helps.
 
Going through that issue myself. My veh was going nuts with lights and locks.  Traced it to the aftermarket remote car start. Truck runs perfectly with fuse removed for remote start however battery is drained overnight with it removed (odd).  Tonight I am using ampmeter hooked to bat leads and will unplug fuses one at a time to see where drain is coming from, has to be after the remote starter fuse in that circuit somewhere. I watched a youtube video for troubleshooting parasitic battery draw. Seems to be easy enough.
 
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