Help with tail light wiring

[Tdbrwn]

OK, we have a late 2017 29.5 BHDS. We had been having an intermittent problem with the passenger side tail light, brake light only. I've already replaced the LED lights on both sides, and replaced the 7-pin connector on the truck. Still, no brake light on that tail light. Turn works, hazards work, brake light on drivers side just not the passenger side.
Does anyone have any idea where, which side, does the wiring harness run to the back of the 5th wheel? All wires at the lights have been checked so the break is somewhere in the harness. How do I get to it?
Any help is appreciated!

[Yooper906]

Originally Posted by Tdbrwn

OK, we have a late 2017 29.5 BHDS. We had been having an intermittent problem with the passenger side tail light, brake light only. I've already replaced the LED lights on both sides, and replaced the 7-pin connector on the truck. Still, no brake light on that tail light. Turn works, hazards work, brake light on drivers side just not the passenger side.
Does anyone have any idea where, which side, does the wiring harness run to the back of the 5th wheel? All wires at the lights have been checked so the break is somewhere in the harness. How do I get to it?
Any help is appreciated!

I would suggest looking up by your hitch where the 7 way cord from the truck splices into the trailer wiring.

[Stan&Sharon]

Hi Tdbrwn,
I had something similar going on with my previous camper. My truck is always looking to confirm the bulbs haven't blown out. Turns out, the truck could not properly interpret the resistance of LEDs and I needed Curt 7-Way RV Blade LED Electrical Adapter

The similar problem (adapter needed) occurred when I installed a new Haloview rear camera. My truck didn't have appropriate current to power it.
You didn't mention your truck make/model but mine is 2021 GMC Sierra 2500. Whenever something's not working though the 7way plug I start wondering if the problem is my truck or the camper. If you wonder too, the troubleshooting technique I suggest is to borrow a friend's camper and/or truck to see for sure if it's my truck or the camper.

[GTS225]

I suggest Stan might be on to something. The pinout for a 7-way shows that only one wire is utilized for both, brake and turn signal function, (either right or left) and it sounds like that side turn signal does operate consistantly. That leads me to think the "road" wiring in your trailer isn't the problem.

Food for thought.....Roger