Troubleshooting Trailer right Tail Light Brake and Turn Signal Not Functioning When Bulbs are Good

Question:

2008 jayco camp trailer, right tail lamp, brake, signal does not work. All other lights work. When the camper is plugged into the tow vehicle 2013 i think suburban, the reverse light come on. I had to install a conntek 7way plug on the camper. The lights worked fine on my 2004 chevy sivlerado. I checked the bulbs and they are not burnt out.

asked by: Matt C

Expert Reply:

Because you know the lights all worked fine on another vehicle, the likely culprit is a bad ground connection. Each vehicle will send a different amount of power to the trailer and that means one vehicle might overcome a bad ground that another vehicle simply cannot. When there are some features that work and others that do not, a ground is the first place to start.

I recommend checking your main trailer ground to the frame, normally near the battery to make sure it is clean of all debris and corrosion and has a clean bare metal connection. Use some sand paper to ensure this and reinstall the screw or bolt. Next check the ground at the tail lights themselves (specifically the right one). The ground is sometimes a separate wire on each side, but often is through the mounting hardware. Make sure these connections are also bare metal to metal.

Finally, clean the pin connections on the vehicle side of the 7-way and then on the trailer side using some sand paper or steel wool. Then use dielectric grease # 11755 to keep dirt and moisture out of the connections. If this doesn't solve your issue, let me know and we can continue to troubleshoot.

expert reply by: Jason S