so I get my truck back (08 f350)and hook the trailer to it and there are 0 lights. I just unhooked the trailer from another vehicle and all lights were working so I know its not the trailer. I plugged a reciver plug tester in and no lights came on meaning no power. I looked in the book and checked fuses but no luck...... I think there was a 10amp fuse inside and 1 outside under the hood if I remember?
what fuses should I check?
2 relays are called out in the book too---- how to test them? switch with another one and try?
thanks.

P.S. when the slide is moved on the trailer brake controller in the dash it lights up and says trailer disconnected- so it does have power

 

I plugged my trailer in once in the rain. My headlights were already on and when the trailer plug touched the truck plug the fuse blew due to all the water. I believe the blown fuse was found in the fuse box under the vacuum pump (engine bay, drivers side, behind degas bottle, under vacuum pump).

 

I noticed you said you got the truck back, did this issue come up after work was done? If so what was done?

 

Yes- vehicle was in for total break job. It hauled the trailer to the shop with my ride home on it- I hauled the trailer to the shop when truck was done- lights worked both times--- I hooked up trailer to leave and nothing..... Possibly coincidence but??