control

i have a 2003 ZR2. Cold air always from bi-level. Turn to heat it does'nt heat up. A/C works great. Turn to floor air still on bi-level, same with defrost.

i need help without having to pay a tech.

can anyone help me

Auto matic or manual controls?
Any flashing or check lights?
May be 2 problems?
Coolant level good and does engine heat up good?
Does both heater hoses get hot to touch?

Have you checked for good engine vacuum to controls?

And vacuum lines on the vacuum ball or good engine vacuum to and threw it?