7-Way to 5-Way Trailer Adapter Does Not Operate Right Turn and Brake Lights, 2003 Chevy Trailblazer  

Question:

Expert Reply:

The adapter that you purchased may be wired or configured differently than your trailer. You will want to plug in the adapter and test the pins on it for function. A traditional 5-Way flat will have the far left pin as electric brakes or for an electric lock out. Since your trailer has surge brakes, it probably has an electric lock out so this pin would need to be connect to the reverse light circuit on the vehicle.

The pin next to that is for right turn and brakes. The next pin is left turn and brakes, followed by running lights. The pin on the far right is for ground. Compare that to how your adapter and trailer is wired and make adjustments as needed.

If everything is wired and configured correctly there could be a ground issue on the passenger side trailer lights. First check that all trailer connectors and adapters are free of dirt and corrosion. Next, check the main trailer ground, it should be attached to a clean bare metal surface on the trailer frame.

The trailer lights should also be attached to clean bare metal surfaces. Most trailer lights ground through the mounting studs. If there is rust or dirt build up, clean it off and reattach the lights.

Finally, you can check the wiring going to the trailer lights. Check for any breaks or nicks in the wiring. You can sue a circuit tester like # PTW2993 to check the wiring for breaks that are not obvious. I have included a link to our wiring FAQ article that may be helpful to you.

expert reply by: Michael H

0