2002 Chevy Silverado Blower fan

My blower fan stayed running after the ignition was shut off. There was a fusee that blew, under the hood. If that fuse is replaced, it immediately blows again. Prior to this problem, I had a few minor (I thought) problems with the blower. It would run on certain speed settings, then it would work on others the next day. Now it does not run at all. Is this a relay? The Motor itself?

Any advice would be very helpful