Has anyone figured out how the temp controls really work?
My '81 has only the three slider controls (although the owners manual shows four) - two in the top slot and one in the bottom slot.  I've met other Vanagon owners that also only have three controls.
I've tried going by the manual but w/o the second of the bottom slot control things don't seem to work as they should.

What does each of the three do in the view of you real users out there?

For normal use I leave the two top slot controls to left; single bottom slot control to the right.
 
For heat I move the top slot lower control to the right.  Moving both to the right seems to still produce the same amount (very little) of heat.  
Also, the heat only comes out of the slots just above the floor on the short 'step' behind the in between seats step.
 
It seems too that air is always coming out of the top dash vents/defroster vents that blow on the window.  Isn't there a control to close these?
Thanks.
    
Scott A. Harvey
'81 westy