Not a really pressing question, but this is Friday, and it is something
difficult for me to check since I drive alone.

Anyway my 1983 VW Owner's Manual shows an illustration and describes the
operation of the four sliders in the Air/Temp control. The 3 air volume
sliders, A, C, & D have a graphic triangle to depict the increase/decrease.
Both A & C logically follow the graphic. IOW, pushing towards the larger end
of the graphic increases air flow.

However for the slide lever D on the bottom, which controls the roof outlets
in the back, the manual says "To increase outside air flow - slide lever to
right"  That's the reverse logic of the above and it puts the lever at the
small end of the graphic.

Of course this confusion is due in large part to my assuming that VW means
to increase air flow to the back. The reverse graphic would only make sense
if it were the reverse and it actually means to increase air flow to the
FRONT, you should decrease air flow to the back. But in my opinion that
would be a convoluted way to describe its' proper operation.

Garrett Adams
83.5 Adventurewagen GL
Stockton, California