I have a 2004, 5.3 regular fuel, Chevy Silverado, automatic, 4x4, club cab.

Here is my problem:

1. Truck starts and runs but battery will run down if not run for a few days.

2. Four instrument lights on -- battery light on, engine light on, airbag light on, ABS light on.

3. No power locks, no power windows, no door chimes, no AC.

4. Remote door locks do not work.

I went through both fuse boxes(Instrument panel fuse box and the under hood fuse box) and all of the small fuses have power to both sides except for the door chime fuse that has no power to either side with the truck running and driver door open. Chimes have not been working since this problem developed.

Q1 - I do not have an electrical schematic for the truck, is there one available on this site or some other place?

Q2 - I don't know how to test the relays or the larger fuses that look like they have a window on them (stud 1, stud 2, IGN A, etc.)?

Q3 - I know that many of the things that are having problems are also associated with the cabin computer. I did buy a used one that has been tested and reprogrammed for my specific VIN number. I'm apprehensive of putting the replacement one back into the truck and then having a possible different problem that caused the inside computer to become bad do the same thing to my replacement inside computer.

Anyone have answers to my questions and possibly other tips or suggestions of where to look or how to resolve this matter? Thanks ahead everyone!

I am the original purchaser of the truck and no electrical modifications have been made to the truck other than an upgraded alternator installed about two or three years ago. Jelly, red top battery installed about 4-5 years ago. Otherwise everything is stock. Some of gauges haven't been working and I'm about to install a new one but want to get these electrical issues resolved first.

 

I tried to plug tester into the OBDII outlet but it would only run tests about halfway through and then stop and would not finish the tests.

 

I'd say body control module. Everything you've posted is tied to that one thing

 

My system is drawing about 1.35 amps when off. Is there a fuse for the BCM that I can pull to see if that is the parasitic draw?

 

Okay, the majority of my parasite drain on the battery is the factory sound system. The CD hasn't worked for years and now it appears it is a primary culprit. When the 15 amp fuse is pulled it drops the draw from 1.35 down to .17 amps.

I'm wondering if the drain of the battery could have thrown off my the settings on my BCM (body control module)? I'll try to reset it and if that doesn't work, then it will be swapped out.

 

What you post, sounds like have a cd stuck

 

No, no CD i stuck in the radio.

I tried replacing the BCM, the truck runs the same. Weirdly enough, I tried to do the quick crank than switch to just on, and the damn thing started right up. The instructions were a ten minute set, then click off when the light came on, then do it two more times.

I've tried to check the fuse boxes for draws and it wasn't working out all that well.

No one else has had these problems?

 

Okay I changed out the PCM. That was the culprit. It was so bad that a few pins had eroded off. And four female receptacles had to be removed and solder new ones on. Did the re calibration/relearn on the computers and it's good to go with all problems resolved and running like a clock! Thank you for the input everyone!

 

Curious - is your sound system back to normal now?

 

I know this is an old post but it happens to ALL these trucks. There will be a hole under thr front driver side fender right under the engine fuse box. Water can now splash right inside the fuse box, corroding all those wires. Guarantee that's the problem. The fuse box has four screws that'll allow you to lift the circuit board over and if it's just corroded, a little contact cleaner will restore all your power. If it's too far gone, it'll probably cost roughly 100 dollars for a new engine fuse box. Somehow you have to patch that hole..a little spray foam goes a long way. Then just slide that new box on and...BAM! I just saved your *** hundreds of dollars and a huge headache. I like chocolate hint hint 😊 happy trails guys!