I don't recall what runs the climate control in that car, but I'm assuming that you don't have a N-22.

If not, there will be a low-pressure switch somewhere on or near the receiver. That prevents the compressor from starting with insufficient refridgerant. Ensure that you get 12V on both wires of this switch when you think the compressor should be running. Don't confuse it with the temperature switch, if you also have one of those on the receiver. The temperaturse switch should have power whenever the key is on, while the low-pressure switch will have power only when the compressor is demanded.

No voltage at the switch means that the problem either power or something in the cabin. Voltage on one side means the switch is bad or you have insufficient refridgerant, voltage on both sides means that the problem is after this switch, perhaps in the compressor clutch or wiring.