Troubleshooting Trailer Running/Clearance Lights With 2005 Nissan Frontier

Question:

I have an 05 Nissan Frontier with a 7 pin factory trailer harness. When I connect trailer I only have signal and brake lights. I have no running / clearance lights on trailer. All fuses under hood are good and truck tail lights are OK. Any suggestions?

asked by: John E

Expert Reply:

On your 2005 Nissan Frontier, the running lights and clearance lights are on the same circuit. Because you have already checked your fuses, the brown relay in your harness has possibly gone bad. We only have this replacement in the Curt Relay Kit for Nissan Aftermarket Tow Package # C57000. The relay on your vehicle should be under the hood in the fuse box. To confirm if this is the issue, use a circuit tester like # PTW2993 to test the 11 o'clock pin on your 7-way when the trailer is not connected. If you have function there, then your vehicle side is working and you most likely have a ground issue or short on your trailer.

On your trailer first check the ground wire connection at your trailer's common ground on the frame. This connection needs to be bare metal to metal and free of corrosion or debris. Next, check the ground at your tail lights. These often will have either an independent ground wire or they ground through the mounting hardware. Make sure those connections are clean and also bare metal to metal. If that doesn't solve your issue, you will need to trace your running light wire from the trailer connector probing every few feet to find a short using your circuit tester and replace the wire as needed.

expert reply by: Jason S