Ok guys and gals, I need to know when vac is applied to the valve, when heat is needed or when heat is not needed? Reason I am
asking, I drove to beach on Friday, with ac running, and a nice frosty 47 at the vent. Stopped over by beach to buy gas and then when I restarted engine, air was warm, not hot, but not cold, no leaks, this morning coming home, air was frosty again! Idling in garage when I got home, I had no vac at valve no matter which way I spun the temp selector 85 or 65

 

Assuming Delanair II, and assuming the heater valve, vac is applied to the valve to close it, the valve is normally open. The valve should close when full cold is selected, and far as I know, only when. The system does take some minutes to respond and set itself though, and if parts of the system give various readings as a result of heat soak etc etc, it might be that it takes a while to get to where it should be.
I could also just as easily be the amplifier, or the rheostat on the cam unit being a touch iffy.

 

Thanks Greg!

 

Just to add my experience, Darren, Nix behaves the same way. When I stop even for gas, it takes some time to cool off again to the temperature it was when I parked it.

When I finally learned that this is how it works, and got over comparisons with 21st century climate control systems (which have us all spoiled), and remembered this was the first attempt at Fully Automated Climate Control, it became a fascination and wonderment to listen to all the bits work and marvel that it works as well as it does.
(';')

 

Ok, I might just leave alone for now, to be fair I turned it off after about 3 minutes of still not blowing cold!!