Determining Correct Wires On Back of 5th Wheel Trailer To Add 4-way Connector

Question:

I have a flat 4 wiring harness for my boat trailer. I found a white, Brown, Red and white wires on back of 5th wheel. Do you know what wires I connect to? Thanks

asked by: Tim

Expert Reply:

Since the wires on the back of your 5th wheel trailer are not the typical colors for connecting a 4-way trailer connector to, you will need to use a circuit tester like # PTW2993 to find the wiring functions.

The 4-way flat connector you have will have the following functions:

White wire is the ground
Green wire is the passenger side brake/turn signal
Yellow wire is the driver side brake/turn signal
Brown wire is the running light/tail light wire

I included a link to a helpful article on trailer wiring for you to take a look at.

expert reply by: Samuel C