Rich,
There is a tray underneath the evaporater.
It has two tubes, one on each side
that exit & drain behind the rear side vents, on the D pillar.
the tube (s) could have slipped off the tray, or leak or be clogged.
also, the tray could have a crack, or leak somehow otherwise.
The plastic is old and brittle.
A helpful trick or two, I found, is to heat the tubing a little
with an industrial blow gun.
Makes it a lot easier to manipulate !
Also, if the tube has a kink in it
you can place a light weight spring
the diameter of the tubes ID
in the spot where the kink is.
Removing and replacing the rear AC,
is not an easy job, no matter how you do it !
I used a couple of coolers and some 4" X 4" X 12" blocks I have
to lower the AC down on.
best of luck,
JC

-------------- Original message --------------
From: Richard Dixon <dickd@SYMPATICO.CA>

> I'm wondering if any owners have had this air conditioning problem: At end of
> last summer during a hot spell, as A/C did its work, moisture started to drip
> above the rear cargo area. Any ideas on repairing this problem?
>
> thanks,
> Richard
> 1988 Vanagon