Interior Air Circuit Problem

[French_Mark 8]

Hi

I have from 2-3 weeks this problem: whatever the circuit I select on the climate control, the air flow comes from windshield defrost circuit.
Temperature control runs well, heating if cold, clim if hot, exterior temp is correct.

Any idea? problem on climate control unit or on servo motors of circuits?

thank you

 

[billcu]

It sounds like a vacuum leak to me. The system defaults to defrost if there is a vacuum leak.

I'd check all the vacuum lines near the intake and firewall first.

 

[French_Mark 8]

thank you
I didn't know it was vacuum actuated as in my old '76 corvette.
The electrovalves on the motor's cover are for that?

I will check

J.