If your compressor clucth is not engaged you may need to check the system with A/C guages. The low pressure switch senses low pressure, usually from lack of freon, and opens the circuit to the clutch. Did it just suddenly quit working?
Could be a bad fuse... I had a 35 amp fuse go intermittent on a Fairmont some years back and it gave me fits... AC worked fine sometimes but not others... replaced the fuse and everything was fine. The fan was on a different fuse so that still worked. Hope its that simple for you too.