Thank you everyone for the alternator help.  I figured out what the problem
was and fixed it last night.  Turns out that is was a loose wire.  I have a
crazy setup with a dual battery isolator and the thing has a wire that
solders onto the regulator inside the alternator.  I noticed the loose wire
and couldn't figure out where the heck it was supposed to go.  Luckily the
PO kept all of the documentation and had the wiring diagram for the dual
battery isolator.  I just had to take out the regulator and solder it back.
Work great now.  Had to trickle charge the battery for a while overnight...
But all seems OK now.

Michael Blackburn
(1990 Syncro Adventurewagen W/GTI)