Troubleshooting Trailer Light Connections for Proper Function

Question:

I have a yellow yellow/brown green green/brown and white ground wiring systum. My lights are yellow and green wire and green and brown wire. Can i hook the the yellow/brown to the brown and the green/brown to the green? I tried that but cant get my lights to work? Can you tell me why?

asked by: Jeremy F

Expert Reply:

My first question is do you have your trailer light grounded to your trailer? If not, that is why you won't get any function because you need to have that ground to complete the circuit. This is often done through the mounting hardware, but some lights have a separate white ground wire instead. That needs to be connected to your trailer frame bare metal to metal.

You need to connect your wires based on function and not color. To determine the factory color functions, use a circuit tester like # PTW2993. Then for your lights you can use a 12-volt battery to determine the light functions by simply connecting the ground to the mounting hardware if there isn't a separate white ground wire and then connecting the positive to one of the other wires.

I've attached a wiring diagram to help further if needed.

Once you have determined the functions of each you can simply connect them based on matching function.

expert reply by: Jason S