Are Trailer Wiring Colors the Same as Factory Vehicle-Side Connector Wiring Colors

Question:

Why does my Manuel for my truck have the green wire for left turn and stop and yellow for right turn and stop and brown for running. Is this a miss print? Thanks

asked by: Jim

Helpful Expert Reply:

The information I found in the online version of the 2014 GMC Sierra's owner's manual lists the colors you referenced as the wire colors used for the functions of the vehicle-side 7-way connector. Vehicle manufacturers do not use the same wire color code as the trailer industry. You can use a circuit tester, like # 40376, to confirm the functions of the wires on your vehicle-side connector.

On a 4-Way flat trailer connector # 18004, the bonded 4 wire # 16-4B-1, and traditional 7-Way trailer connectors # PK12706, the yellow wire is for left turn/stop, green is for right turn/stop, brown is for running lights, and white is ground.

We always recommend wiring by function, rather than wire color. Colors can change between manufacturers, so function is the best way to be sure your trailer and connectors are wired correctly.

I have attached our help article on trailer wiring for you.

expert reply by: Victoria B