How to Wire New Taillights on a Trailer with Yellow, White, and Black Wires

Question:

I have a horse trailer Im trying to replace the taillights. The wires on the trailer are black, yellow, and white, the light kit I bought is red black and white. How am I to match these up?

asked by: Shari

Expert Reply:

I cannot be for sure but if I had to guess; the white wire on the trailer is for the ground, the black wire on the trailer is for the running lights, and the yellow wire on the trailer is for the stop/turn signal. I would also speculate that the red wire on the light is for the turn/brake, the black wire on the light is for the running lights, and the white wire on the light is for the ground. With that being said the harness could have been replaced at any point in time not to mention that not all trailer manufacturers used the same color wiring so it is always best to test them with a circuit tester.

expert reply by: Conner L