I recently picked up 1990 s10 blazer sport 4x4 for $300 as a driving project. It failed state inspection because the defroster isn't working. It was on the vent setting when I picked it up and the blower worked on all speeeds. When the climate control is switched to any other option, it blows the dash fuse instanty. I replaced the fuse and checked each climate option and all but the vent setting blows the fuse. Also the blower isn't working on vent anymore. I was told the control switch was bad. I pulled it and inspected and didnt see any problems.I thought it was probably the blower motor. Any advice before I swap both out?