How to Connect 4-Pole Trailer Connector to Trailer Wiring With Two Running Lamp Circuits

Question:

This is for a 4 flat connector...I have 2 brown wires coming from my trailer why? My van has the standard regular colors yellow, green, white, brown...

asked by: Solo G

Helpful Expert Reply:

Your trailer has what's known as a wishbone harness, where the running light circuit is split into two legs, one for the right side, one for the left. Other trailers will just run the running lamp circuit down one side to that taillight, then daisy chain over to the other taillight. Wishbone harnesses are frequently used on trailers with marker lights on the side.

To attach a connector like the # 18004, you'd simply connect the two brown running lamp circuit wires and join them with the brown running circuit wire from the trailer connector.

expert reply by: Mike L