The main feed for the VDO cluster comes in on the plug below the speedo. You will see that the blue plastic circuitry has a + and - printed in it. It is the same plug that takes in the speedo signal from the rear diff.
As for the dimmer it is not a simple rheostat but a rather 'nasty' piece of circuitry with all sorts inside, a couple of chips plus resistors and and capacitors! From experience it is exceptionally difficult to take apart!
The 3 light bulbs for the cluster illumination are usually 504's (3w W2.1 x 9.5d). Control panel (switches) are usually 1.2w W2 x 4.6d. Both are capless.
These pics might help.
Bob
