Troubleshooting Trailer Wiring That Stops Working When Headlights are On

Question:

I brought a 2003 dodge caravan sport all the blinkers work when the running lights are not on but once I put the running lights on none of them. Work what COULD cause this not good with electrical Please help

asked by: Timothy

Expert Reply:

This sounds like a classic ground problem. A bad or weak ground will show up when there is more load on the system. That is why when you turn the vehicle lights on, the constant draw of the trailer running lights creates more of a load and the bad ground shows up.

There are some common places to check for a bad ground. First make sure all of the trailer lights and the main trailer connector are attached to clean and corrosion free bare metal surfaces.

expert reply by: Jameson C