I'm also having problems with my AC. I bought the car on from a "lemon lot" on an Air Force base. Ever since i bought the car only one setting works on it when you turn it on. Only the highest blow mode works. What do i need to do to fix this problem?

I have a 2001 and I replaced the AC controller and it works fine.
the only problem now is that I hear a pulsing hum at 40 mph when the AC is on.( any clues?)

Probably just need a blower motor resistor. Usually high speed works because it is direct power form a battery to relay.

About how much does the resistor cost for it?