Wiring New Trailer Lamps With Black and Red Pigtail Wires

Question:

I have two new trailer lights w two wires black and red on both , on wiring harness there is a red and yellow going to the left side . Does the red harness wire go on the red light wire and yellow go on the black wire to the light ?

asked by: Ben

Expert Reply:

I'm assuming your're speaking of a stop/turn/taillight such as # TLL160RK. A yellow wire carries the left turn/left side brake lamp, so the remaining wire would be for the running lamps. If the lamp has only two wires, it'll ground through its connection to the trailer frame or to a metal part of the trailer that's connected to the trailer frame. If the lamp is to be attached to something non-metal that isn't attached to the trailer frame, you'll want to run a jumper wire from the mounting hardware to the trailer frame.

If the trailer lamp is a marker or clearance lamp, the red will go to power, and the black wire should be the ground.

expert reply by: Mike L