I'm working on my sis's 02 and for some reason we have no aux trailer power at the trailer plug. All fuses under hood are good and there is no dummy fuse in there. Every spot that should have a fuse does! I also checked all the fuses in the dash as well. I'm getting stumped!

Do the wires and back of trailer connector look corroded at all?

We took the trailer plug apart and it looked ok. We did clean it up a little and still nothing.

Here's a diagram for the circuit, looks like it runs through the IP relay block, maybe a problem in there.

I'm working on my sis's 02 and for some reason we have no aux trailer power at the trailer plug. All fuses under hood are good and there is no dummy fuse in there. Every spot that should have a fuse does! I also checked all the fuses in the dash as well. I'm getting stumped!

Because that wire has power on it all the time it is also usually the first to corrode. Have a look underneath behind the plug for obvious wire damage.

Might want to check the connections under the truck and then follow those lines back under as I believe there is another junction under there somewhere, just not sure...

Pull the cover off the fuse box under the hood and I bet you find the wire not even hooked up to the post.