air conditioning and heater elect problem. maybe related to radio also. on 1992 Chevrolet 1500 Pickup

when I start the truck the a/c light flashes, but the air does not work. Is there a computer card that is related to the air conditioning, heater, and masybe the radio?

have the dreon checked at a shop. that is probably the reason for the flashing ac light. the radio is another problem