How to Wire Trailer Lights That Have Yellow and White Wires

Updated 08/17/2015 | Published 08/15/2015

Products Featured in This Question

16 Gauge, 4 Conductor Bonded Parallel Wire - Per Foot

(237)

$2.47

Optronics LED Trailer Tail Light - Stop, Turn, Tail - Submersible - 10 Diode - Oval - Red Lens

(2165)

$15.99

Question:

Should one light wires be browm or green

asked by: Bob B

Expert Reply:

With the Deka Bonded 4-Pole wire # 16-4B-1 that you referenced the usual wiring configuration is the white wire is for ground, the brown wire is for running/clearance lights, the yellow wire is LEFT turn and stop and the green wire is RIGHT turn and stop. If your trailer lights have two wire leads and one is white and one is yellow, then it is likely that the white wire is ground and the yellow wire is hot. If the light does not have metal mounting studs, which can sometimes be the grounding point for trailer lights, then it is likely that the light you have is a single- or two-function type.

A light with three wires and no grounding stud, such as Optronics # STL78RB, is a 3-function light: stop, turn and taillight. On this light the white wire is ground, the red wire is turn signal and brake and the black wire is taillight.

The linked article on trailer wiring may be helpful to you.

expert reply by: Adam R