I've been following this thread with rapt attention.  I have instrument
cluster problems as well, and I was wondering if the experts might weigh in
on what they think might be the culprit.  "Compost" is a vehicle I acquired
from my folks.  They had an instrument cluster failure at one point and
ended up having a junkyard replacement installed.  Here's the deal with the
replacement:

1.  Tach goes out intermittently.  Usually it works fine, but it'll drop to
0 sometimes when driving.  And then it'll come back occasionally.  No rhyme
or reason.
2.  When the tach goes out, the rest of the right side of the cluster will
go out as well (usually, although recently I've been having just tach
failures).
3.  When the right side of the cluster is working, the temp gauge seems
accurate.
4.  The gas gauge is really inaccurate.  I wonder if it's a cluster issue or
the sensor in the tank.  When the tank is full, it reads pretty close to
full.  However, it drops not linearly and I end up showing in the reserve
when I have as much as a 1/2-3/4 tank remaining.
5.  The odometer is stuck at 204242. The trip odo doesn't work either.  I'd
love to have a functioning odo again.

Thanks, ladies and gents!

--
1985 Brown Vanagon GL 4spd "Compost"