It was the Other one.  Of course.   I just moved my power lead for the new
tach light onto the other white/blue stripe wire and found that to be the
one controlled by the thumbwheel.
  Should have just used the meter first time around, but I had a feeling I
would soon have the instrument cluster out again anyway..For some reason,
I've been doing that a lot lately.
  Thanks,
  Don Hanson

On Thu, Dec 24, 2009 at 4:17 PM, Larry Alofs <lalofs@gmail.com> wrote:

> If you have a voltmeter, you could see which one changes when you move
> the thumbwheel.
>
> Larry A.
>
>
> On 12/24/09, Don Hanson <dhanson928@gmail.com> wrote:
> >      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
> >
>