Wish I knew one too I've got a 1990 Chevy Subarban 4x4 Silverado. The A/C controls aren't working right I put them on defrost and it has air comming out of the dash vents and the defroster vents also when I put it on heat the heater blows out of the dash and the floor when it's supposed to blow just on the floor (atleast it did when the car was new).