Troubleshooting Trailer Running Light Circuit on 2014 Nissan Frontier

Question:

My trailer lights stopped working. They did worked before. The directionals work and the brake lights work just not the tail lights. I checked the harness and there is no power on the brow wire.

asked by: Joe R

Expert Reply:

Since you tested your vehicle connector and found no signal on the running light contact you can check all fuses and relays related to trailer lighting. A bad relay is not really easy to spot so the best way to check is just to replace it with a new one to see if things start to function again. We offer Nissan relay kit # C57000 or you can get them locally.

If there are no bad fuses or relays then next check the ground wire for the connector where it attaches to the frame. The grounding point must be clean bare metal that is free of paint, primer, grease and dirt. The ground wire ring terminal must be tight to this bare metal to make a good ground. Very often a bad running light circuit comes down to a bad ground.

You can also check where the vehicle's connector # 118263 plugs in. Use a tester on the vehicle side connector contacts to see if the running light signal is there. If it is then you need to replace the 4-pole part # 118263. If it is not trace the running light wire further upstream to find the point where the signal is lost.

expert reply by: Adam R