Troubleshooting Trailer Wiring that Acts Strangely with Taillight Circuits Activated

Question:

I have a 4×8 folding/tilt lawn trailer, all new wiring and lights..the ground in the wiring by connector is a new drilled hole and was grinded clean and is tight, when I turn on running lights I have running lights on trailer however, when turn signals are used both trailer lights flash and when I step on brakes the lights go out, when I let up on pedal lights running come back on...there are no brake lamps. Ive tested plug on truck all work and lights are self grounding threw bolt holes new lights..any ideas?? Im confused beyond belief thanks.

asked by: Walt W

Expert Reply:

Bizarre trailer lighting behavior like what you described is characteristic of insufficient ground on the trailer wiring. This is even more common on folding trailers like you have since the wiring grounds through the frame. Best option is to make jumper wires from each assemblies ground back to the main ground harness of the trailer and the lights will start working like they should.

expert reply by: Jameson C