Archived Blinker brake light problem

[JNapier]

My son has a 01 dually with no flashers, blinkers, or stop lights. He can not find a blown fuse and replacing flashers hasn't seemed to work. He is on the road trying to get back home. He pulls trailers for a living. We think one of the trailers was wired wrong, don't really know. HELP, JNapier

 

[JApol]

Are the lights not working on the trailer or the truck?

 

[Bob4x4]

There is a 40 a fuse(#8) that powers up the trailer tow relay in the pdc.