Troubleshooting Trailer Brake Lights that Go Out When Headlights are On

Question:

I have a 14ft boat. Just bought brand new light kit with wires. Everything works except when my running lights are on my brake lights go out when I push them. I read a bad ground could be the problem. I have changed it and can not even have the ground hooked up and the same thing. I have hooked to different vechiles and same thing. Please help

asked by: Russell

Expert Reply:

There are two sets of grounds you need to check. The grounds for the taillight assemblies and the main ground for the trailer that runs from the trailer connector to the frame of the trailer. Between one of those grounds lies your problem as what your are describing is a textbook example of an insufficient ground.

Another possible solution (although unlikely) is that you are overdrawing your trailer light circuits from your tow vehicle. You may have installed too many lights on the trailer and now it's overdrawing and shutting off.

I attached a couple helpful FAQ articles for you to check out as well.

expert reply by: Jameson C