Need help: Vent shuts down while driving (96 Regal)

Hi,

I have a 96 Buick Regal Custom 4DR 3.8 Series II engine. This car has a push button dual climate control. When I am driving with the AC on and the control set to Vent, the air from the vent goes on and off. It looks like there is a loose connection or something. Is there anything I could check myself before I go to the mechanic?

Thanks,
Maurycy