I am working on my  new tach. 84 vanagon.  Just installed an
aftermarket tach yesterday and it works well but the light doesn't go dim as
I dim the other instruments.  I took the power for the tach light off one of
two wires that go into the dimmer part of the headlight switch.  White/blue
stripe in my 84 van.  Up at the multiplug that connects the instrument
cluster to it's foil circuit board, the Bently says the instrument light
power comes from a white/blue stripe wire, so I am guessing (not having the
patience to pull apart the rat's nest of wires in the under dash bundles to
follow that wire through to the intstruments) I have the proper wire.  But
maybe I got the supply to the dimmer wheel and not the output from that
reostat(?)

  So, I have it all apart again today to replace the master cylinder for the
brakes and I wanted to get the tach light to dim with the other lights.
There are two white/blue stripe wires meeting in  the headlight switch
dimmer "wheel".....did I simply choose (and I did just take a chance,
picking one, figuring I could be right) the wrong one of those two?  Can I
just move the lead to the tach light onto the other white/bluestripe, or
could I go up nearer the foil multi plug and get the white/blue stripe up
there?

  Or should I take some scrap window tint and stick it on the tach gauge
face...(semi joking)

  Thanks in advance,  Don Hanson