> My mother has a recently purchased '87 Vanagon Wolfsburg Ed. There
> is a noticable and uncomfortable draft of warm air comming from
> under the dash.  I haven't seen the van, but she claims to be
> turning off all of the heater controls. This is more and more
> annoying as temperatures rise in mid summer.
> 
> Is this a common problem? What's the diagnosis and what's the fix?

I don't know if it's a common problem or not, but I had the same
problem with my own (recently-purchased) '87 Westy.  After some
troubleshooting, it turned out that the coolant valve controlled by
the temperature slider (the one that goes from red to blue) was
defunct -- it was always allowing some hot coolant through to the
heater core under the dash.

It was an easy part to find and replace.  It's just inside the bump in
the center of the floor right under the dash -- there are two coolant
hoses and a cable running down into a rubber plug.  Pull the rug back
and you'll see it right away.  The valve's just under it -- the cable
and one of the coolant hoses connect to it.  You'll also have to pull
the spare tire and get underneath the car to do the change.

The valve cost me $12.  Fortunately, they used the same valve in a lot
of Rabbits too.  It wasn't hard to find.

I'm having a similar problem with the rear heater now, and I assume
it's the same thing.  Haven't dug into it yet.

J