Problems With Light Functions On Trailer After Installing 7-Way Connector

Question:

I replaced my factory trailer connection with a OEM. I matched all the wires by color except that the OEM has a yellow wire and there is a red wire coming from the truck side. All lights work on the trailer but when I apply the brake the lights go out on the trailer. I guessing I have the brake and stop light wires crossed up but not sure which way to go Can you help?

asked by: Stan C

Expert Reply:

When you are installing a trailer connector like part # PK11893, you can run into issues due to the wires that the vehicle manufacturer used have different colors.

This is why we always recommend using a circuit tester, like part # PTW2993, to test the wires on the vehicle side, and make sure the wires on the trailer side connector match by function and not by color.

I have attached a helpful article that explains trailer wiring you can check out. In the article there is also a helpful chart that breaks down the functions on a connector. You can also check out the photo that shows what each of the pin functions are on a 7-way connector.

When working with electrical connectors I recommend using dielectric grease like part # 11755. This keeps dirt and moisture out of the electrical connections and helps prevent corrosion.

expert reply by: Jeffrey L