Hi Rich (and All),

        I've just recently figgered out my heater controls on my 86.  The recent
Alaska winter weather has necessitated I learn.  Try moving the bottommost
heater contol lever to the far right (no outside air in).  The next lever
seems to work best when positioned fart left (function unknown).  The other
two seem pretty straightforward.  Anyways....worked for me.... good luck....
stay warm

Scott De Santi
86 Vanagon