Switching Trailer from 7-Way to 4-Way and Right Turn Signal Does Not Work

Question:

Im trying to wire a 4 pin on a trailer that was a 7 blade I have brake lights, auxiliary and left turn signal but cant seem to find the right turn signal

asked by: Bryan

Expert Reply:

On a 7-Way blade style trailer connector the brake lights and turn signals are on the same circuits. So you will have one for left turn and brake lights and another for right turn and brake lights. If the brake lights are working on the right side then the turn signal should also be working.

If it isn't then there is likely a ground issue. 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 but can show up any time.

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.

expert reply by: Michael H