Hi,

Been reading this forum for a while and finally have a question I can't find an answer to.

I have the upgraded 7 wire towing harness with the red, dark blue and, light green wires. RPO code UY7

I had to fix the 4 wire harness on the car, as it had the brown wire going to the reverse lights, and the white wire(ground) wasn't even hooked up.

I have repaired that, and now I get 12v on the running lights, and ~4v on the left and right brake lights without the brakes depressed.

However, I now have a new issue: I am trying to use the red wire as a 12v power for something (reverse camera), and the reverse lead to trigger the head unit, sounds great, but now I don't have 12v at either location(reverse lead only when the vehicle is in reverse).

Does anyone have insight to what could be causing this? It is driving me crazy after I spend all evening wiring this up all nice and pretty.

 

There are separate fuses for all of the trailer circuits in the underhood fuse panel. They can be identified by the TRL prefix in the fuse panel cover. Check both terminals on the top of each fuse with a test light or DVOM while the circuit is activated, (ignition needs to be in the RUN position while testing). Post your results.

 

Captain, I found the trailer reverse fuse, and it was blown. I replaced it and it is working fine (will monitor to see if it blows again), but the red wire in the harness (battery charging on trailer) is not listed in the fuse panel. Can you shed any light on what I should check?

 

Depending on what year the vehicle is, there's usually a separate "MAXI" fuse in the underhood fuse panel for battery charging. 50amp seems to ring a bell, and it may have been removed, or never installed. Check the owners manual, if you can't find the answer, let me know.