sorry to bump this dead thread, but I'm having almost the same issue and i've done some searching to no avail.
since I know nothing about A/C's / HVAC and I'm kind of iffy in taking an engine swapped car to a shop to work on it (I have a recently purchased 92 SC with a 1JZ swap)., I would like to try to diagnose what's going on.
I've been told by the previous owner it's probably the condenser, but from my reading, it's more likely that it's a missing signal.
the fan blows fine, and the heater works great.... but it's over 90 degrees here in Cali and I'd really like to get this fixed before I have to drive hours to the nearest race track lol....
how do I tell if the condenser or another part of the a/c system is bad and who should I enlist the help of?