Trailer Lights Go Out When Using Brake Lights and Turn Signals or Running Lights at the Same Time

Question:

I wired it up as stated. Have good ground, turn signal, right and left and tail lights. But when I turn on the tail lights the turn signal quits on converter not truck. Same thing with brakes. Turn on a turn signal it works hit the breaks and no turn signal.on converter only

asked by: Daniel V

Expert Reply:

This sounds like a ground issue or a potential overload situation. Ground problems normally show up when there is more draw on a system such as when you have the running lights on and then use another function like a turn signal or brake light. And overload could be the result of a short or too many lights on a trailer.

Make sure that the vehicle side and trailer side connectors are clean and free of corrosion inside and out. The main connector grounds should be attached to clean and corrosion free bare metal surfaces.

The light grounds should also be attached to clean and corrosion free bare metal surfaces. If there is anything between a light ground and the metal trailer frame or if the trailer has an aluminum frame, tilt bed, or folding tongue, any of these things can interrupt the ground. Running jumper wires from the light grounds to the main trailer connector ground can help.

Inspect the power wiring to the trailer lights and if there are any pinched or exposed wires fix as needed. To determine if the lights are drawing too much power you can try disconnecting some lights. Then, if everything on the remaining lights starts working properly then it was probably too much power draw for the converter. Switching to LED lights would solve that problem.

expert reply by: Michael H