I have a similar problem on my '92 only it works fine sometimes and not others. I thought for a while it might be the switch on the HVAC control module(?) itself but after a little trouble shooting that doesn't seem to be the problem.
My best guess is it's the AC relay (on my car, not necessarily yours).
edit:^this is my legitimate attempt to help^

I've searched on this site and although I've found references gallore, never came across how exactly to replace it. I know it's not too hard but anyone out there replaced the AC relay on their 5th gen who could give me some advice or point me towards a walk through?
edit:^this might be considered a derailment, I hope not, wasn't my intention^