My '97 S90 has started blowing the main 20amp AC fuse. It will produce nice cold air sometimes for up to 15 min or so, then only warm air. Subsequent check shows fuse blown. Replace fuse, cold air for sometimes only seconds. Compressor clutch sounds healthy enough. I checked the AC wiring in the engine bay, and there was definitely sign of heat at compressor connector, which was loose. I replaced the connectors with nice tight new ones, thinking that excessive resistance right there might be the cause of the slow-blow. No dice. Obviously it's not a short, as it doesn't blow instantly. Anyone know what can cause abnormally high resistance in the AC circuit? I've seen reference to seized blower fans being a problem on some cars. Thanks in advance for ANY input. Heat index over 100F here.