Troubleshooting Trailer Wiring To Get Stop/Turn Signal Function

Question:

I have a 2018 ram 1500 with trailer package and everything is good coming out of truck, Repaired ground wire on trailer. My question is when i stripped back the ground wire to put a new end on it the ground wire was blackish not copper colored? Is that telling me the ground wire is bad? This seemed to start when a trailer clearance lite went out and found a broken wire. i got new one from you guys and it works great now. Dont know if there is a connection that cause this when the fender light went out? The trailer is a 2015 RC 6X12 enclosed trailer if you need that information. Thank you for your time.

asked by: JOHN N

Helpful Expert Reply:

Great question. It sounds like the trailer ground wire has had power on it at some point. It sounds like you have remedied any issue, however I would replace that ground wire. I recommend using # 10-1-1 to trade that wire out so you have a ground you are confident in. When you have the ground wire on a bare metal surface, then you can troubleshoot the brake and turn signal wires.

Since you know the truck side works, I recommend first checking and cleaning the connections. Then since you know the running lights work and the ground will be fixed, then you can use a circuit tester like # PTW2992 to test the stop/turn signal wire on each side. If you have signal, then you know the ground connection of the specific tail lights needs to be grounded bare metal to metal which is often through the mounting hardware but can be a separate wire.

expert reply by: Jason S