OK, the early Vanagons do indeed have this feature as my '81 has the four
levers with the lowest one sending air into the rear of the cabin, out the
vents over the sliding door.  The passage is there on the driver's side
too, but is covered with a block-off plate before it even gets to the
driver's door.  Obviously on a Westy, there are no upper vents on the
driver's side in the rear cabin.

The passenger Vanagons do indeed have upper vents in the rear cabin on both
sides and so the passages through the doors are functional on both sides.

As far as the vent at the rear of the door with the blue lever, that is not
connected to the vents for the rear.  Those doohickeys are supposedly for
"fresh air circulation."  Our vans are supposed to be airtight.  VW was
known for that.  So theoretically, if you want any fresh air coming into
the van, you need to provide an outlet so you get a flow-through kinda
thing going.  That's what those flaps do.  You open them and you supposedly
get better ventilation as the air coming in doesn't have to "work as hard"
to get in.

That's the theory behind them anyway.  Note that the air-cooled Buses also
had those vents in the doors.

Sean

> I'll try this one.  The Vanagon (and I presume Caravelle) versions had
> vents in the upper rear cabin area for fresh air.  There are four levers
> on the dash control.  The fourth (bottom) lever opens a fresh-air flap
> at the bottom of the heater unit.  This allows air to travel through a
> metal channel in the dash (which makes it a bitch to get to anything
> under there, through the doors, up the door posts and through to the back
> vents.  The Transporters all seem to lack this lever, flap, gaskets and
> vents.  The early Westfalias were built from Kombi models, and also
lacked
> these.  Later Westies were built from "Camper" bases, and this feature
was 
> on these.  I have only seen the vents on the passenger side, and the
> driver's side probably does nothing (I don't have a late westies, so
please
> correct me!).  The passenger versions have vents on both sides (two per
> side in the rear).  I am busy adding these vents to my doublecab, but
have
> not started to change the heater unit to one with the proper flap.  The
> DC has fixed rear windows (as does the Kombi) and really *needs* the
> ventilation.  
> 
> The blue lever on the lower doors does not connect to this system on any
of
> my versions.  It is also not covered in my owner's manuals.  I have no
idea
> what (if anything) this contraption does!  I am a believer that VW never
> spent a cent they did not have to.  Anybody know what the blue lever
does?
> My '80 is in the Bay Area so I can't check, but I thought the function of
> this thing was covered in *that* owner's manual.
> 
> malcolm
>