Troubleshooting Trailer Lights That Dont Work When Vehicle Headlights Are Switched On

Question:

The video was very helpful. The only issue that I have is that when ever I turn on my headlights the lights on the trailer does not come on. Can you please help me figure this out?

asked by: Bruno O

Helpful Expert Reply:

So, everything works fine until the vehicle headlights are switched on, is that correct? This typically means that there is a weak or insufficient ground connection somewhere in the system. On the vehicle, check the ground connection for the # 118426 converter. Make sure the ring terminal on the white wire is securely connected to clean metal. Make sure the ground wire on the trailer (usually connected to the trailer tongue) is secure and not corroded. Check your trailer lamps, which pick up their ground connection either through a dedicated ground wire or by their mounting studs being in direct contact with the trailer frame. Make sure these connections are tight, and not being interfered with by any corrosion.

I'll also link you to our trailer wiring troubleshooting help article. If you examine the items listed above and still have the problem, please get back with me and we'll look into some other possibilities.

expert reply by: Mike L