Way to test A/C?

Is there a way to test the A/C on a 1995 Yukon to see if the problem exists with the controls or the A/C system? I have an A/C system that went out, but am suspicious it may be the controls and not the A/C itself. Before I start throwing parts at it, want to track it down further.

Does the A/C clutch pull in and start the pump. That's the quick and dirty of the pump control operation. After the pump starts it's pretty much a mechanical thang. If you have refrigerent it should be making cold, if not take it to a pro. Because of the high pressures involved and the enviornmental regulations it's not a user servicable system.
Other controls are usually vacuum acuated valves that route heat/AC air to the heater core or AC evaporator. If you move the temp control the temp should change, moving the outlet control should change the place the air is routed to, head. body, defog etc. If you have a broken vacuum line the whole system just stays where it was.
Good luck, see ya
94