Another thought, the blower rotor is stalling (screeching sound). it may intermittently seize up. The fact that you state the fan is now working OK to me eliminates the fuse. The screeching noise sounds like a dry bushing in the motor. Or you may have some foreign object in the blower case that gets into the fan rotors and the falls out. I had this on my 87 BMW. The squirrel cage just disintegrated. What a racket.. Check it out. If it does seize up, you will burn out the motor if the fuse doesn't fry first..
2000 Dodge Grand Caravan SE