I have 97 s14 and I've had it for a while now but the problem is that the ac only works on 4 none of the others the heater works also but just on 4 too. I changed the AC unit with a different one but it still only worked on 4 im guess it something with the wiring. So if anybody had this happen to them or just know how to fix any help will be appreciated. Thanks

 

There is a resistor box down by the blower motor (under/behind the glove box). When that burns out, it only works on 4. They're cheap and easy to find.

 

thanks ill look into it.