Right Turn Signal and Brake Lights On Trailer Dont Work

Question:

Tail light and turn signal on right side of trailer not working. trailer has breakaway battery

asked by: Shawn D

Expert Reply:

There are a couple things you can check to determine the cause of this. Start with the wiring harness and make sure that it is free from debris and corrosion. Clean it off if necessary. Next check the wiring harness connector using a circuit tester like # PTW2993 and make sure that you're getting power from all of the poles. If one of them is not putting out power, the issue is on the vehicle.

If your vehicle connector is functioning correctly, the issue will be found on the trailer. Start by checking the ground connection on the trailer and make sure that it is firmly grounded to a paint and debris free spot on the trailer; you'll also want to trace that ground wire back to the harness to make sure none of that wire is damaged. Do the same for the wires that correspond to the tail lights and right turn signal on your trailer connector and make sure that they aren't damaged as well. You'll need to replace any damaged wires as required.

If this still hasn't located the problem, let me know and I can continue to help you out with some other troubleshooting steps. I've also attached our article on troubleshooting trailer connections for you to refer to during this process.

expert reply by: Erik B