Troubleshooting Trailer Lights that Stop Working When Running Lights Are On

Question:

Hello, I have a 2014 grey wolf travel trailer. A year ago i had to replace the tail lights. Since then i have never been able to wire them up correctly. I know im crossing the wires somewhere, but dont know which one is there any place ir website i could go to get the right wiring diagram. As of now the turn signals work. The hazards work but when i turn on the lights nothing works. Help please.

asked by: Michael G

Expert Reply:

It sounds like there is a ground issue on your trailer, which makes itself known only when turning on the running lights because this requires a bit more power. A weak ground might be enough for certain functions to activate by themselves like your turn signals and hazards, but when an additional function like your running lights are turned on, there simply is not enough power to go around.

I recommend checking that your main trailer ground is connected to a clean, bare metal surface free of any corrosion or debris. Also, especially since the problem occurred since replacing the light assemblies, you will want to make sure that the lights themselves have a solid ground connection. Many trailer lights will ground through the mounting hardware, so check to see that they are securely attached to a bare metal surface.

Lastly, check both the vehicle side and trailer side connectors for any dirt or corrosion inside the pins that might be causing a short.

If you are unable to resolve the issue, please let me know and I will be happy to look into this further.

expert reply by: Chris R