My 2004 Chevy Silverado 2500HD is having an electrical issue and I need help to find it. I have an idea on what happened but may be just a coincidence. A year ago I took the truck in for service on the rear end. At that time I had them repair a hanging map light console on the ceiling. It all works great and truck runs great. BUT every morning the trucks battery is dead. This started a few months after repair, at first I replaced battery but a few days later it was dead again. Everything works like it should, no lights are on at night. I think Alternator is ok because it holds a charge all day, with multiple starts. But after sitting for long period of time it gets weaker until it can't turn over. Where would you start? Can I just pull the fuse for the overhead console? See if it holds overnight without draining? DO you know what fuse to pull? Maybe the DMM? I an electrician who doesn't know much about auto electrical. Thanks for any help

 

I had an issue with a company lease vehicle, I think it was an 06, intermittent same issue. It could set for 2 weeks, start right up, drive 500 miles, next morning no crank. Dealer said it was battery, replaced it, no change. Never found out what it was, I believe the radio was causing it. If it is doing this on a regular basis, my suggestion is when you stop it for the day, pull the radio fuse, if the problem goes away after "time", you've found it.

 

Put an amp meter in the battery line and see what you leakage current is, then start pulling fuses until it goes away, that will be the bad circuit.

 

Can I use my electrical FLUKE DVM for amp meter? It is only a 10A capable and only has probe type leads. I assume we are looking at less than an amp for leakage

 

Fluke DVM is perfect, take off one of the battery cables and put it between the battery and the cable, 10A range. Make the connections how ever you can, probe and duct tape come to mind. Once you hook it up and everything settles down I would think your are looking at something in the 500mA range or less.

 

You really just need to look at voltage, and yes it will be millivolt drop as you pull individual fuse's. As I stated since what you have is intermittent, I would recommend pulling the radio fuse after you are done with the truck for the day.

 

I had a Problem like this with my S10. the alternator was drawing 4.2 amps with engine shut off.
I found it by removing the negative lead from the battery and connecting my meter in between lead and post. pulled all of my fuses 1 by 1 with no success, disconnected the alternator and Boom... no more Amp draw. it would take 2 or 3 days to kill the new battery I installed because the old one was a Wal-Mart special and exactly 5 years old so naturally....
Good Luck