I followed the instructions in the box my tach came in.  The "simple" way
is to run a wire from the coil to the tach.  But, the coil's in the back of
the bus, so you have to run a wire up to the dash.  I've  previously run a
4-strand "trailer connect" wire from my engine bay to the dash to run my
other add-on gauges anyhow, so it was very easy.  I'm guessing there is
some wire you could get a tach signal from that might already be somewhere
up front, but I find it bothersome fishing around under the dash in all
those wires.  I did trace the instruments light wire to a blue/gray teeny
little one to connect the new tach's night lights to the dash light's
dimmer function.
On Feb 2, 2014 7:04 AM, "George Laubach" <skiplaubach@comcast.net> wrote:

> I would like to add a tach (like Don, except without the
> pre-work/time/frustration of dealing with the foil) to my '84/Digijet. Is
> there a write-up for the "30 minute install"?  AKA, where do the wires go?
>
> Thanks,
> Skip
> Illinois
>
>
>
> Sent from my iPad
>
> On Feb 2, 2014, at 8:46 AM, Don Hanson <dhanson928@GMAIL.COM> wrote:
>
> > I tried the "move the pins, etc" to put a Vanagon tach into my 84, with
> > lots of frustrating and relatively expensive failures. I spent a lot of
> > time removing and re-removing the clusters and foils trying to resolve
> oil
> > pressure warning system anomalies and dealing with those minute
> > connectors.   I finally decided a small modern aftermarket tach, which I
> > mounted dead-center on the cluster in about 30 minutes.  I spent about
> $20
> > on that and it's giving good readings, though it IS just a bit too bright
> > with it's LED backlights.
>