When ever I turn my blower/fan on, it blows the 20 amp fuse. I put in another fan from one of my parts cars and the the same thing happens.

Any ideas?

Merci.

 

Make sure the squirrel cage portion of the fan is freewheeling inside the fan enclosure. If the cage is too far down on the fan motor shaft it will bind up inside, it's hard to tell.
Otherwise look for a dead short some where, i.e. a bare wire.
hanman