My defrost fan doesn't work, so I checked the fuses and they blown. When I replaced the fuses and turned on the fan I heard them imediately blow. I am wondering if the problem is just the fan or something in the dash wiring. If anyone has any ideas I want to try and get some advice before tearing into the dash. I'm hoping there is a simple solution, and replacing the fan is no biggie, but I don't want to fiddle with any more wiring than I absolutely have to.

This sounds like a short to ground. Odds are, it's either the switch, motor, or relay. If you have a loose wire with an in-line fuse, and another for ground, you can rule out the motor fairly quickly. Just run the ground side to a ground (block, battery, whatever) and the hot side (with an in-line fuse) to the positive post of the battery. If the fuse blows, the motor is gone. If the fan turns, remove and bypass the switch. If the fan still turns, replace the relay. It is highly unlikely the wiring is bad unless rodents have been making a home in your dash (it happens). It's also pretty unlikely a bad realy would blow a fuse. So, unless you know something about the problem you're not sharing, I'd suggest testing the motor and switch first.

 

Kalo

More than likely it's the fan - they wear out after a few decades.