This is my first post here, so go easy on me.

I've got a '92 SSE, and I'm having trouble with the A/C / heat switch, or at least I think it'* the switch. When I go to turn on the A/C, the compressor does not engage. Also, the airflow won't change to defrost.

Is the switch bad? Could a relay be out, and if so, which one? I was also told that it might have something to do with a vacuum line.

Any thought or ideas would be extremely helpful. My son will be taking this car to college in the next month, and I don't want to sink a bunch of money into the fix if I can do it myself.

Thanks in advance!

Slight correction... it'* a 92' SE. Must be nervous, being it'* my first post and all.

check if the clutch engages and then disengages because it has no freon...

Also, do all your other functions work on the switch?

The compressor does not engage when you turn the switch to A/C or defrost. Nothing seems to work when the switch is in any position. The airflow will not change from floor only to floor and vents or defrost.

I own a 93 SSE so it should be the same. Since your airflow is stuck on the floor, you have either broken linkage behind the **** (unlikely) or have lost vacuum in the system. There is a vacuum line that goes from the intake area, directly over the rear exhaust, to the firewall. This is right at the back of the engine compartment in the middle where only a basketball player could reach it. The heat from the exhaust cooks the hose and it becomes very brittle. Replacing it with a regular vacuum hose usually only buys you another year or so. I replace it with a much longer line and route it to the drivers side, back to the firewall (leaving slack here for the engine to move) then over to the middle again. This avoids being directly over and close to the rear exhaust manifold. Start the engine and change the setting to MAX and see what happens. Also, check your other vacuum lines and replace them as necessary with regular vacuum hose. It is usually a good idea to replace all your vacuum lines when the first one gives you trouble. Leaks and kinks anywhere in the system cause too many problems.