That's it, Yea that looks like a super clean connection.

 

Yes it sounds like a short. It can be anywhere. I suggest to start with that fuse that keeps on blowing. Pull out the relay box and open it up and unravel the wiring. Find the wire that comes from and to the fuse then trace that wire all the way to where ever it goes. That is the only way to 100% find the problem. Pulling the entire wiring harness out of the truck will help.