Troubleshooting Trailer Light Functions Not Working and Wire Colors Not Matching

Question:

I have a KZ camping trailer. I just read your wiring tips today and my wires do not match up. To start with, I have a red wire that seems to be operating my left turn signal and brake. Your chart does not even show a red wire. My brown wire seems to be operating the right turn signal and brake not the tail or running lights like your chart shows. The bottom line my running and tail lights are not working on the trailer.

asked by: MICHAEL M

Expert Reply:

Sometimes companies have different wire colors, so you will need to check functions instead of color. You can use a 12V battery for this with a couple jump wires or your can connect it to your vehicle and use a circuit tester like # PTW2993. You can use the locations of the functions in the attached photo to assist. If you match the functions and still do not have running or tail lights, you most likely have a bad ground connection on those lights. Make sure you have a bare metal to bare metal connection. To make sure this is the issue, you can simply run a jump wire from your ground wire on the light to the negative battery terminal of your vehicle.

expert reply by: Jason S