How Do Trailer Wires with Two Wires Attach to 4-Way Trailer Wiring

Updated 04/07/2015 | Published 04/06/2015

Question:

I bought a new set of lights for my trailer that have a red and brown wire on them how do they hook up to a 4 wire set up .

asked by: Howard S

Expert Reply:

Based on the colors of the wires that are on the lights you bought for your trailer is sounds like the assemblies ground through the mounting hardware, the brown wire is the running light circuit, and the red wire is the stop turn circuit.

A traditional 4 wire trailer setup has a stop/turn circuit that runs to either side of the trailer. One for the passenger side (typically green wire) and one to the driver side (typically yellow). So that's two of the four wires. The white wire will be the ground circuit that can be run to the light assemblies or to the frame of the trailer, and then the brown wire will be the running light circuit that will split off to both sides of the trailer.

I attached a help article on trailer wiring for you to check out as well.

expert reply by: Jameson C