Today my pregnant wife is driving along and all of a sudden the a/c stops blowing out of the vents. I can't figure out where the air is going, the blower motor is blowing hard but the air is not getting out of the vents, or the floor, or the defroster. The knob on the dash has no effect on the air flow direction, I.E. you can turn it to defrost and nothing and on floor no change, it almost seems that that switch is bad. there is a VERY weak air flow coming out of the vents but here in Texas in June and July it gets hot and my wife is VERY pregnant. Has anyone had this happen to them, and what can I do to fix it?