Troubleshooting Trailer Taillights that Stop Working When Headlights are On

Published 10/12/2016

Question:

Bought a hitch and light kit for a 2009 Nissan Rouge roughly 3 years ago. All worked fine until about a month ago. The running lights on the trailer no longer are powered with the headlights on. Brake Lights, turn signals all function correctly. Is this a problem with the conversion box in the vehicle itself? How can I fix this? Thanks!

asked by: David M

Expert Reply:

Your main problem is an insufficient ground for the trailer wiring. Try improving the connection of the main ground wire of the trailer wiring harness. Make sure it is attached to a clean metal surface. Or you can run all of the trailer wires back to the main ground. This is actually the ideal solution. But you can also check the current grounds for the lights to make sure they are making a solid connection to a clean metal surface.

What you described is the classic insufficient ground scenario so finding a way to improve the grounds will fix the problem.

expert reply by: Jameson C