IMO you definatly have a cut wire somewhere. It could also be a bad switch. Id pull the radio and start there, inspect all the wires then check all the switches on that circuit. It could be a door pin switch, one of the int lights or just a bare wire that has been rubbing up against somthing and finally wore through.

For me it was the wire that powers the mirror on the passenger side sun visor. it had a splice in it and was shorting out on the metal L that the visor was mounted to.

It did the same thing you mentioned, put a fuse in poof! disconnect the batt put a fuse in and hook the batt back up and poof! I couldnt get a fuse to last 5 sec and it only took me a month to find

Good Luck man, electrical problems can be a nightmare.