Fix for Trailer Wiring that Stops Working When Headlights are On

Question:

Blinker are dim they work on the rite elamen turn the lights on and they quit working lights work

asked by: Scott M

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. The pins of the trailer wiring connectors should be checked an clean as needed too.

What you described is the classic insufficient ground scenario so finding a way to improve the grounds will fix the problem. When the headlights of your vehicle are on that's when it's drawing the most amperage which is why an insufficient ground would show up then.

expert reply by: Jameson C