1991 Ford F150, headlights, brake lights and turn signals all work fine but no front or rear running lights (tail lights). I've checked the fuse and it has power to both sides. Could this problem be related to the trailer hitch wiring? Not sure but the problem SEEMS to have started when the trailer was plugged in bacwards.
I'm stuck! Any suggestions.
Pull the switch out of the dash or at least get where you can look at the wires Ok find the brown it may not be hard to spot it will be the burnd up looking one take a test light and turn the switch on test lite the brown wire if you have no light pull the plug out of the switch I bet you will find it melted. The wire is not heavy enough to hold the load of the truck and the trailer. And if trailer was wired wrong it feed power to ground and burned the wire up. The brown wire is the whole key from front to back.(NOS)