hvac

We have a '12 Traverse. It was just at the dealer's for a driver's side airbag issue and a problem with the 60-side of the 2nd row not wanting to fold. Both cheerfully handled under warranty by Gordon Chevrolet on N. Dale Mabry in Tampa. What they didn't do anything about was the HVAC controls...

I have a 94 silverado and appear to have and electrical issue. The hvac was working on and off for a couple months, but now has quit working altogether. When I adjust the temperature, it adjusts, but there is simply no power blowing the air/heat out. Also, the wipers seem to work sporadically...