I have an 04 ranger (4.0 liter) and the trailer lights are not working. I know the trailer lights and wiring are good because I plugged it in to a buddys truck. This is the first time I have tried using the wiring harness on the back of the truck. I checked the fuses that I thought could be the problem. I had one blown fuse. It wasin the fuse box in the engine compartment and it was either for left or right signal towing. I replaced that and still no lights. any feedback would be appreciated

 

Get a meter and check the pins directly. try with the ground lead in the ground plug as well as to a good ground on the truck itself. The start chasing