Thank you for your post. Sorry to hear you're experiencing this issue. After researching your vehicle's Owner's Manual pg. 3-19 Climate Control; it mentions the fan must be turned on to run the air conditioning compressor. For vehicles with air conditioning, follow these steps to use the system. Turn fan to the desired speed. The air conditioning does not operate when the fan control knob is in the off position. Press A/C to turn the air conditioning on and off. When A/C is pressed, an indicator light comes on to
show that the air conditioning is on.
If your A/C continues to malfunction, I recommend having it serviced at your local GM dealership. Please keep me posted.
Vanessa,
GM Customer Service