Adding Running Lights to Trailer with 5-flat Connector

Question:

I have a five wire plug-in and I want to add side running lights to my trailer Can I just took the white wire ground the white wire ground on the trailer in the hot wire to the brown wire or one of the brown wires

asked by: Herbert H

Expert Reply:

It sounds like you have a 5-way flat on your trailer for the lighting functions; running lights, turning and brake and the fifth pin for the reverse lock out on a hydraulic brake coupler. The white wire on the light is the ground function and can be grounded to the trailer frame or spliced into the trailer connector ground wire. The brown wire needs to be wired to the running light circuit.

Traditionally, the running light wire on a 5-way is brown but I am not sure which color wire is the running light wire on your trailer but you can test the functions using a circuit tester like part # PTW2992. Have someone sit in the vehicle and run through the functions to see which color wire is your running light function and attach the brown wire from the light to that.

expert reply by: Heather A