Trailer Lights Shut Off When Hazard Lights In Tow Vehicle Are Applied

Question:

I have a trailer that has all the lights work but when the hazard lights are turned on from the truck. They are not working. What could be causing this?

asked by: Austin

Expert Reply:

I assume you mean that when the hazard lights are applied in the tow vehicle, the lights on the trailer no longer illuminate. If that is the case then what you are going to want to do is check your ground wire connection points. The most common cause we see when lights go out with multiple circuits active is an insufficient ground that gets overpowered and shuts down. I recommend that you run all of the lights on the trailer up to the main ground for the trailer side trailer connector. If this is already done then remove the main ground, sand down the surface, and reattach with new hardware.

If the problem still persists once the above is checked then the issue may be on the vehicle side so it would be a good idea to check the ground for the vehicle side trailer connector as well.

expert reply by: Conner L