I have a 1993 F-250 with factory wiring for the 7 prong trailer wire. My running lights quit working recently on the trailer. I took a battery and hot wired the D prong on the trailer and they work. I checked the D prong on my truck and it is dead. All fuses in the fuse box check OK. Is their another fuse somewhere in the line to the back of the truck? Any help would be greatly appreciated.
Yes all 92-96 body stile trucks have the Trailer marker lamps relay with or without the factory towing package.
This relay will also control any of the extra marker lamps on the truck. The only ones it does not control are the parking lamps on the front and the rear corners.