I'm trying to help fix my neighbor's truck which i use for a tow vehicle for my tbird track car. It's a 2000 Chevrolet C2500 (3/4 ton truck).
Here's what I've found so far:
1) The STOP/HAZ fuse (20AMP) in the dash fuse panel blows pretty quickly when you press on the brakes. After that, the rear turn signals and brake lights stop working.
2) If you replace the fuse, the hazard lights work without any issue and the door chime works.
3) In an effort to trace the issue back, I have removed the following: the wiring panel for the truck bed lights (in case there was a short there - I recently replaced the bulbs with LEDs), both rear tail light panels (I replaced the pass side one a few months ago), and the wiring going to the trailer lights and rear light harnesses. The STOP/HAZ fuse still pops immediately upon application
Here's what I think is going on:
* All that's left on the car is the wiring harness coming from the dash rearwards to through the frame rail.
* I found the wiring diagrams for this car on autozone.com and I believe the issue might be the stoplight switch shorting out mounted to the brake pedal.
* From one of the diagrams, it seems like the STOP/HAZ fuse feeds into three circuits: stoplamp switch, convenience center/chime module, turn hazard switch. Since the last two circuits seem to work without blowing the fuse, I'm thinking its the switch.
My current plan is to just pick one up from AZ, work my way underneath the dash, hopefully remove some of the extra wiring crap my friend put in this truck (like the lowpass filter+bazooka), and pray that replacing the brake pedal switch fixes the problem (at least test it BEFORE installation).
I also plan to fix the shoddy wiring I found at the rear end (like how the trailer light harness was tied into the stock wiring) but I'm not sure that will fix the issue.
Q: What do you think? Any other ideas on what could be the root cause of this issue?
In one of my wiring diagrams, i did see mention of a rear lamps bussing block. However, when I looked for mention of this online, all I could find was a video. I do NOT seem to recall seeing this back there on a C1500 truck so I'm not sure if this also applies to a C2500. Furthermore, if I did disconnect things between the frame rail and the wiring harness at the rear of the truck, I don't see how this could be the culprit in my specific shorting situation.