Troubleshooting Trailer Brake Lights not Working

Updated 08/03/2017 | Published 08/01/2017

Question:

Have 2005 Pacifica, wired for a trailer, but the converter seems to be not working, because I have no signal lights and Brake lights when hooked to the converter. If by pass the the converter, I can get signal lights, right is dim, running lights ok, but no brake lights.

asked by: Ronna

Expert Reply:

Often when some lights are working but others are not, the issue is a weak ground. The main ground wires need to be securely attached to a metal surface that is free of dirt, corrosion or paint. You also need to make sure the brake light assemblies on your trailer are grounded, which is often done through the bolts of the assembly so long as the housing is attached to the trailer's frame, and that frame is metal.

Should the ground be okay, the next thing you will want to do is use a circuit tester such as # PTW2993 to check that the signals are going into the converter box from the vehicle side. Have someone engage the functions while you use the circuit tester.

You will also want to check all of your wiring to see if any of your wiring is damaged, that the bulbs in the lights are still working, and that your connectors do not have any corrosion. If corrosion is present, it will often be white or green, and you may be able to clean the connectors. I have also linked a pair of help articles on wiring for you to take a look at.

expert reply by: Kyle S