Wiring a 3-Wire Trailer Light with White Black and Green Wires

Updated 02/24/2017 | Published 02/23/2017

Products Featured in This Question

ONE LED RV Tail Light - Brake, Tail, Turn - Passenger Side - Rectangular - Surface Mount - Red

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$15.83

Hook Probe Circuit Tester

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$12.08

Question:

Im trying to wire this tail light up. It has 3 wires, white, green, and black. What goes where? When turn signal is on or brakes are pressed, lights work as they should. However, when running lights are on, neither brake light or turn signal comes on.

asked by: Trevor S

Expert Reply:

A trailer light with 3 wires, like # RVSTL0060, that are black, white, and green generally the black wire is for running lights, green is for stop and turn signal, and white is for ground.

If the old light on your trailer only used 2 wires, then it likely was grounded through the mounting hardware. Which means you'll need to find a good ground bare metal location to connect the white wire to.

Make sure you check the function of the trailer's wiring before connecting to the new light with a circuit tester # PTW2993 before installing.

expert reply by: Charles S