Troubleshooting Non-Functioning Trailer Turn Signals

Question:

I just rewired my boat trailer all the wires are fresh the left turn blinks both the right turn doesnt blink anything

asked by: Garrett I

Expert Reply:

In standard RV-type trailer wiring the turn signals and brake light signals are combined onto the green wire for the passenger side lights and on the yellow wire for the driver side lights. If the vehicle and trailer are wired correctly pressing the vehicle brake pedal should deliver a brake light signal to both sides of the trailer, on both the green and yellow wires. Activating the turn signals should only affect one side of the trailer.

Quite often when trailer lights misbehave the cause if a weak ground connection. I suggest checking the main grounding point for the trailer's plug. This white wire with ring terminal needs to connect to a clean bare metal spot on the trailer frame, one that is fee of paint, primer, rust or grease. If you do not have bare metal grounding point I suggest you sand off a small spot on the trailer frame and re-attached the ground there.

If your individual lights do not use a separate ground wire this means they use their mounting hardware to establish the ground. In this case you may need to sand off the light's mounting point to allow for a good ground at the light assembly.

Once you have the ground corrected you can help protect that connection with an application of dielectric grease like # 11755.

expert reply by: Adam R