First off, using standard colour codes, the brown wire is running lights.
Before you get much further though, your profile doesn't show what truck you have, Ford uses a double fuse setup. There's a second fuse box that has seep rate fuses for the trailer harness. If you have a dually, the marker lights on the rear fender flares are connected to the trailer harness so you can easily see that the trailer has no marker lights if you blow a fuse.
I'd start by testing that there's power coming out of the plug you're connecting the camper to.
