i bought the car not too long ago. i noticed that the add. fan fuse was blown. i replaced it with a new fuse and turned my a/c on. the a/c pump was making a bunch of noise and i smelled something burning. i popped my hood and noticed that my add. fan (which was like brand new before i put the fuse in), was completely melted. not only that, the wiring that lead to the whole a/c system was all fried together. the pully on the a/c pump rattles like hell whether the a/c is on or not.

Sounds like there was a short and you replaced the fuse with one of too high a rating, causing the wiring harness to burn. Take the car to a reputable shop for diagnosis and repair.

I just wnated to comment that I too had a failure of the A/C auxiliary fan on my 92 Mazda Protege LX. However, this failure was not nearly as severe as described in the post above: in my case the fan bearings failed, making horrible noise. Replacing the fan fixed the problem.
This happened around 75K miles on the car.

the pump is completely fucked. the car has a rebuilt engine in it, so i think the guy who put it in fucked something up.