How to Install a 4-Way On a Trailer that Uses Non-Standard Wire Colors

Question:

I bought a new plug with white, brown, green, and yellow wires. My old trailer wires are red, white, blue, orange and grey. Which ones goes together? I have a 2002 GMC 2500 truck

asked by: Becky

Expert Reply:

Your old trailer wires aren't standard in color unlike the new 4-way you bought.

The colors of the 4-way you bought are:

White ground
Brown Taillight
Green Right Turn/Brake
Yellow Left Turn/Brake

Since your trailer's colors aren't standard you would need to determine what the function of each wire is and then wire it accordingly to the new 4-way. You can do this by tracing each of the wires back to where see where they terminate or you can use a car battery and a jumper wire to put 12 volts on each of the circuits to see what taillight circuits activate.

Check out the FAQ article I attached on trailer wiring as well.

expert reply by: Jameson C