Troubleshooting Trailer Lights that Stop Working When Headlights of Vehicle Come On

Updated 10/09/2018 | Published 10/08/2018

Question:

Own a 2009 Jeep Grand Cherokee. When I hook up the camper all lights work. When dusk hits and the headlights automatically turn on the camper lights turn off. I have new connections and all ground wires are on a clean surface. The battery on the popup charges as it should. Just the headlights are not working properly.

asked by: Jeannine E

Expert Reply:

Either your trailer wiring's running light circuit is being overdrawn and it's shutting off your lights all together or the more likely situation is that you need to improve the ground of your trailer's wiring and you'll see the lights start to work. When the headlights are turned on the highest lighting amperage draw is put on the vehicle so a weaker ground will show up in this situation. Try running a jumper wire from the ground wires of each assembly back to main ground of the trailer wiring.

expert reply by: Jameson C