You can use the early speedo with the late cluster. There are work
arounds, easy ones. Look at Bentley pages 90.22 and 90.23.

The 86+ blue foil plugs into the back of the speedo housing to connect
to a small circuit board inside that makes the oil pressure warning
light work. If you don't have the circuit board the oil warning light
won't work.

If you have the little circuit board you can just plug the foil into it
and let the board hang there behind the older model speedo. You will
need to bend the outside end pin of the group of four to the side so it
does not go into the hole it was meant for. Pin 6 on Bentley page 90.23
is the pin that should be pushed aside.

If you don't have the little board or don't want to use it you can push
the legs of a resistor into the correct 2 holes of the plug in the blue
foil. Radio Shack sells the resistors for 5 for $1. Get 470 ohm, 1/4
watt or 1/2 watt.

http://images.thesamba.com/vw/gallery/pix/486175.jpg

Mark

Jeff Davis wrote:
> Hi all,
>
> This is my first post to the list so hello all.
>
> I have a 1984 GL Wasserboxer w/Speedo, w/Trip Odometer, &w/Analog
> Clock, w/Coolant Temp gauge.
>
> The instructions from Old Volks Home state you can't use your original
> speedo when upgrading to an instrument cluster from an 86-91. Does
> anyone know why or if there is a work around?
>