Troubleshooting Trailer Wiring that Stops Working With Headlights on

Question:

When turn my back head lights on I dont have any turn, stop, or back lights, but with my lights of I do have turn, stop lights. Note: when the headlight are on the tail lights are brighter, what wires did I get wrong when I wired the trailer?

asked by: Bruce

Helpful Expert Reply:

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