>  Should I bother trying to make this one work in my 84 GL, since the
> connections >are so different than anything I have seen referenced
> anywhere, or should I >attempt to translate the proper wires'
> positions in the "tech/Tach article" and >pull em out to put onto
> this one I have now?  I paid just $20 for the whole >cluster housing
> with only the tach head still inside, but it looks like it has >not
> been damaged or abused and should work, if it's appearance and
> condition are >an indicator of how it's been handled...

when i had an 80 bus, before any vanagons had tachs, i was able to get
a rabbit tach to work in my bus. :) it was a LOT of work to get the
housing of the tach to fit into the vanagon console, but on the 2nd
junkyard $20 tach, i managed to not bugger it up or break the needle.
;)

anyway, i only needed three wires ....
power from the dash lights to illuminate the tach at night.
ground to the chassis for the illumination light.
and a signal wire from the #1 terminal on the ignition coil.

didn't have to connect it to the blue foil thingie at all.

it wasn't very pretty when the instrument console/pod cover was off,
but it worked. ;)

not sure what your 4th connector would be, though ...

good luck! hope it helps.
joel