Went on a trip yesterday and the AC was working fine for the first hour of the trip, but then suddenly started to blow warm air so I turned it off and used nature's air conditioner for the rest of the trip. I pulled over later to check and see if maybe my AC lines had frozen (indicative of low R134a), but all my lines were pretty warm. A further inspection showed that the little 10 Amp fuse in my relay box that is connected to the AC was blown. I turned my engine off and replaced it, but when I turned my truck back on it instantly fried the new fuse. I checked all the visible wiring I could see and didn't see any frays or apparent metal to metal short goin on. Any ideas on what else I could check, short of sucking it up and taking it into a mechanic to gouge me apart? The only 3 ideas I currently have are (a)Bad wire somewhere, (b) Bad AC switch in my dash, (c) Blown AC compressor. Thanks for any help.