Hmmm, I assume we're talking about the blower fan for the cabin and not the blower fan for the radiator. My '86 had a blower fan issue where the bearings were too tight and it took too much current to turn the blower motor. Though the fuse never blew, I did notice how hard it turned while trying to clean a plugged evaporator. So, is the motor free from obstructions and binding. If the fuse opens, that's your safety valve, so an electrical fire doesn't occur. Does you mechanic know what the current draw is from the motor? What was the original fuse rating? 30A is quite a bit of current when you think about the alternator only puts out about 65A.

The reason a fuse blows is because there's not enough (electrical) resistance (short circuit) or there's too much consumption of current. Basically, there are too many electrons (current) trying to ride the bus (wire) at the same time.

Hope all that helps.

Michael B.

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Power Generation Specialist.

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We judge others by their actions.