What is the Power Wire for and Running Lights Not Working on Trailer Wiring Harness for Toyota Rav4

Question:

What does this wire do in the system? Also noticed that when the lights are turned on it is sometimes takes two on off operations to turn the taillights onfor the trailer, is this normal?

asked by: GARY D

Expert Reply:

The power wire in wiring harness # 118412 actually provides most of the power for the trailer lights. This helps protect the vehicle wiring.

The lights should come on when you turn on the vehicle lights so what you are seeing is not normal. Check the connections at the tail lights and look for any dirt in the connectors or a bent pin. Also make sure that the converter box is grounded to a bare metal surface.

On the trailer side make sure the main connector ground and the grounds for the lights are also all connected to bare metal surfaces.

expert reply by: Michael H