Expert Reply: On a 4-Way flat trailer wiring harness, white is the ground, brown is running lights, yellow is left turn signal and green is right turn signal.

Beside above, which trailer wire is running lights? How Do Utility Trailer Lights Wire Up to the Trailer Wiring Harness. The red wire is the turn signal wire and will be run to the green wire of your harness if its the right turn signal side, and the black wire will run to the brown wire of your harness.

what is the color code for trailer wiring?

Trailer Wiring Colors Each connects to a different function: Brown wire to the tail or parking lights. Green wire to right turn signal/brake light. Yellow wire to the left turn signal/brake light.

How do you hook up trailer wires?

Install the Wiring

Position Your Wiring. If possible, feed the wires through the hollow opening of your trailer frame in the front where the trailer attaches to the ball hitch on your vehicle. Attach the Ground Wire to the Trailer. Connect the Brown Wiring. Connect the Remaining Wires.