The A/C has a self diagnostic system if you have the testing equiptment. A dealer could likely tell you pretty quickly.
How to Retrieve a DTC
The audio-HVAC display panel has a self-diagnostic function for heating, ventilation, and air conditioning system. To run the self-diagnostic function, do the following:
Turn the ignition switch OFF.
Turn the fan switch OFF.
Set the temperature control dial on Max Cool, then push the mode control button to select Vent.
Turn the ignition switch ON (II).
Press and hold the recirculation control button.
While holding the button down, press the rear window defogger button five times within 10 seconds. The recirculation indicator blinks two times, then the self-diagnostic will begin.
If there is any problem in the system after self-diagnostic is finished, the recirculation indicator will blink Diagnostic Trouble Code (DTC) 1 through 6. If there are any problems in the evaporator temperature sensor circuit, the A/C indicator will blink DTC 7 or 8.
If no DTC's are found, the indicator will not blink.
The fuse is #30 under the hood.
Most likely cause is that your freon is too low.