Only Passenger Side Brake Light Works on 2008 Jeep Compass After Installing Trailer Wiring Harness

Question:

I have everything hooked up correctly for both the rear drivers side and passenger side wiring harnesses. I am able to only get the passenger side brake light to work on the vehicle. Would the passenger brake light work if I had an improper ground on the drivers side? Using a volmeter i get no voltage on either harness connection on the drivers side, and I get the proper voltage on the passenger side. Both turn signals do not work.

asked by: Rob C

Expert Reply:

A bad ground can cause all sorts of problems, but I am not convinced this is a ground problem. However, it could be beneficial to try to move the ground location to see if that helps.

Wiring harness # C55050 receives power for the trailer lights from the vehicle battery and only a little bit of power and signals from the vehicle tail light wiring. If the power wire is not connected, the harness should not work.

Try disconnecting the harness from the vehicle tail lights and plug the tail lights back in like normal. You should have working lights. This would indicate a problem with the wiring harness. Check the connectors on the wiring harness for any bent pins. A bent pin that is not making contact could cause some problems.

Make sure that your ground is attached to a clean bare metal surface, check the pins in the connectors for any bent or broken pins, and make sure the power wire has a solid connection to the battery. If you still have issues then it indicates a problem with the converter and it will need to be replaced.

expert reply by: Michael H