How to Configure Light Wiring on a Truck and Trailer that have Different Color Wires

Question:

I am trying to connect my trailer that has white red black and brown wire to my truck with a green yellow white and brown wire what colors do I connect with what it seems as though I dont have a right and left blinker wire Im not sure but if you could get back with me that would be great I have no side lights just tail lights on the trailer so Im just dealing with running lights in the back brake lights left and right turn signals and thats it please help stumped

asked by: Stephanie K

Expert Reply:

Typically the color wiring found on a vehicle and trailer for the lighting is as follows:

Green - Right Turn/Stop
Yellow - Left Turn/Stop
White - Ground
Brown - Tail/Marker

As you have found, not everybody follows this pattern and so it can be difficult at times to know the correct configuration.

What you will want to do is use a Circuit Tester # PTW2992 and test the pins on your truck while running through the different lighting functions. Once you know what the wiring is on your truck you can then use an alternate power source, like the 12V battery in your truck, to test what the different wires on your trailer run to.

After you run the testing it is a simple matter of matching up the functions.

If you match all of the functions up correctly but you are still experiencing some issues just let me know and I can help you troubleshoot further.