Troubleshooting No Running Lights on Trailer

Question:

All other lights work on tralier. Turn,brake and stop. Just no running lights

asked by: Michael M

Expert Reply:

If all of your other light functions are working properly on your trailer then it sounds like you have some damaged wiring or a bad ground on your running light circuit.

To determine if the issue is on your trailer or your tow vehicle take a circuit tester like part # PTW2993 and test the location next to the pin on your vehicle 4-Way or the pin in the 11 o'clock position on your 7-Way (see attached photos). If it is receiving power then that means the problem is on your trailer, otherwise the problem is on your tow vehicle.

Either way, check all of your wiring on that circuit for any places where it is damaged or pinched and replace as necessary. If those look good then move on to your ground connections, making sure that they are securely connected to a clean, bare-metal surface.

expert reply by: Jon G