Tail light/stop light wiring

[kyleag89]

Hey guys I've been battling several issues on my 2011 sierra 1500 for a week now.  The newest one is the rear passenger side tail light and license plate light were out.  I looked up the diagrams on gmupfitters and it shows a brown wire from the fuse box under the hood to the distribution block mounted behind the rear bumper.  What I found in reality is that there are 3 brown wires 1 for left, 1 for right, and 1 for trailer connection.  The wire for the right had no power and I've checked the fuses and they're all good.  Is there anything I'm missing or is this actually a possible break in the wire?  In all my years wrenching I've never found a wire to break without something obvious that broke it.  Anyways it's 11pm here and 20 degrees so I'm calling it a night.  I've traced the wire back as far as the gas tank and stopped.  Tomorrow I plan to ohm it out from the fuse to the distribution block.  

[kyleag89]

To clarify I'm just wondering if there may be something else causing this wire to not have power?  Right now my fuel pump control module is bad and I have it bypassed with a relay so I can drive my truck for the best week until the replacement arrives.  I connected the high speed tan wires together so that the coms system is intact still then just used the red power wire to a relay to the pump.  The dark green wire from the ECM triggers the relay.

Edited December 8, 2024 by kyleag89

[tbarn]

Make sure you check under the fuse block. That area is notorious for rodent damage.

[kyleag89]

I didn't get to look at it today but I did some more research online and think that the wire is question comes from the fuse box.  It then goes to the front passenger side turn signal/parking lamps and splits off there somewhere to go to the rear.  I was hoping someone had this problem before and knew exactly where the wire runs.  My loom is in bad shape the tape is crumbling and the loom itself is hard and sharp.  My fingers are all cut up from messing with it 2 days ago!  The clips that hold the fuse box down are all broken on my truck so I try to stay away from messing with that so I'll probably check everywhere else first only to discover it broken under there and create other problems in the process. That almost always how it goes for me.

 

For now I spliced the wire onto the trailer plugs brown wire power feed.  I could leave it like that but I'd like to put it back the way it is supposed to be in case I tow sometime and it may overload that circuit.

 

Edit: looking over some more diagrams the brown wire comes from fuse #27 labeled RT Park and splits off under the fuse box(unfortunately).  I'll update with what I find today.

Edited December 9, 2024 by kyleag89

[kyleag89]

Solved this problem!  It was the tiniest bit of corrosion on the fuse contacts that I couldn't see until I removed the fuse box.  The contacts are literally like a 22awg metal wire and barely have any contact area at all so corrosion can break contact easily!  I've been a GM guy my entire life but man the NBS trucks took a plummet in quality from the previous body style.  Most of my loom has crumbled and  broken away as well as the tape the factory put on.  What tape hasn't already fallen off is hanging on by a thread.  Almost everything plastic on this truck I touch breaks it's so brittle and this truck isn't my only one like this.  I had a 2012 before this truck and it suffered all the same things as well as the dumb fuse box retainer arms being broken.