The way it works is that because of the sharp corner at the front of the
doors, a low pressure area is created, which sucks air through vent slots
at the front of the doors on the inside edges.    The inside of the door
actually has two airmoving functions, which are isolated from each other.
These are the air exhaust function (as above), and the fresh air conduct
that takes incoming air  from the front of the van (inlet over the radiator
grill) and passes it through the doors to the side vent passages via the
fabled fuzzy gasket.

Problem with this system is that it makes for lots of wind and road noise
entry, so on late model vans ('90 and '91?), the inlets in the doors are
blocked off and there is a corresponding blocking gasket at the front of
the doors to seal out wind and road noise.   Air exits through those black
vents in the rear windows.

Our '90 Westy is significantly quieter than our '87 in the front, as a
result of this, so it does work.

Dave

At 02:34 PM 6/24/97 -0500, Linda Bartnik wrote:
>
>
>
>> 
>> Removed "the vent at the rear of the door with the blue lever".
>> Used a flashlight with a small mech's mirror to brouse around.
>> Can find no air passages to these vents.
>> Yet air flows!
>> Is it leaking through the window seals and door handles?
>> Larry
>
>That's the theory, I believe.  It just vents the air to the inside of the
>door and lets it go out drain holes, etc...
>
>Sean
>
>