Is there some sort of actuator or vaccum control that needs to be replaced?
I like to use the heat on BI-Level when the top is down and its under 70 deg which is alot here in Idaho :)

I can get heat and A/C no problem. I can get defrost up top and lower heat but when I change the knob to bi-level or in your face it doesnt blow any air.

Please help! I have spent hours looking for the solution.

Thanks in advance.

Hi Waz… I had a similar problem on my 2001 Z28 and took it to a radiator shop. I could get all the A/C I wanted but no heat and no de-frost. They showed me a bad cable actuator behind the center console a little towards the passenger side that didn’t move (went to the heater box area). They replaced it and did a coolant flush for me. It only cost me about $180.00 for the hole thing and I live in the San Jose Bay Area. I think it was a deal.