How to Determine the Wire Functions on Trailer Tail Lights for Installation

Question:

Hello, I have a 20foot snowmobile trailer that Im rewiring. Ive followed all wires to there proper loc. now, at the taillamps I have three wires on lamps, Correct me if Im wrong Left side- yellow on harness to red on light. Brown black. White wire on taillamp to what Right side- green on harness to red on lamp Brown black. White wire on lamp to what I have a set of three lights in middle of bumper, which wire will run over to these on rt. side, the white one! Thanks so Much

asked by: Tim

Expert Reply:

Traditionally the white wire is the ground. Red would be turn signal and brake lights and brown would be running lights. If you check the back of the light assemblies it might actually have a little code that indicates the functions of the wires.

On typical trailer wiring, especially if it is aftermarket wiring, yellow is left turn and brake lights, green is right turn and brake lights, and brown is running lights. White is the ground. So what you have indicated sounds correct.

The lights in the middle will get wired depending on what their functions are. If they are running lights only then they will get wired in with a brown wire. If you want them to be brake lights only though you would have to use a special converter, # 118158, which takes the combined circuits and separates them out.

expert reply by: Michael H