Troubleshooting Tail Light Converter and Tail Light Circuit on Trailer Towed by 2007 Nissan Frontier

Expert Reply:

So the brake lights and turn signals are working fine but not the running lights, is that correct?

Step one would be to use a circuit tester like part # 40376 on your current trailer connector. Test the pin that corresponds with the brown wire leading to the trailer connector. If this light shows power while the headlights on the vehicle are activated, the problem exists on the trailer itself and not on the vehicle. Trace the tail light circuit which is usually the brown wire back along the trailer from the connector to the tail lights. Look for any loose or broken connections, pinched wires or missing or nicked wire insulation.

If you do not get a signal on that pin, leave the headlights on and trace the trailer connector wires back on the vehicle to the converter. Test the brown wire entering the converter on the input side for signal. If you have power entering the converter but not exiting it, you have confirmed that the converter is bad. At this point, you will want to examine that running light circuit on the trailer to find out what shorted out the converter. You will not want to install a new one without fixing what caused the old one to fail.

For the 2007 Nissan Frontier, we recommend part # 119176KIT. This is a powered converter that draws voltage from the truck battery to fire the trailer tail lights instead of through the tail light circuits. This provides for a more reliable connection as well as protecting the truck wiring.

I will provide a copy of the install instructions for the powered converter below. We also have a video that demonstrates how to troubleshoot a converter. I will provide a link to the video as well.

expert reply by: Mike L