the wiring harness modifications list is in the archives, and on the
backup vanagon list.
since most people are lazy these days, here is the excel file with the guide.
sudhir

http://userpages.umbc.edu/~sud1/vanagon/vanagon_instrument_panel_swap_guide.xls

On 1/2/07, Rich Bennington <rich.bennington@charter.net> wrote:
> <
> Date:    Sat, 30 Dec 2006 17:28:32 -0500
> From:    Jonce Fancher <streetbugs@WHISPLLC.COM>
> Subject: Tach install from vanagon to vanagon
>
> Hi all
> Well I aquired a 84 wolfsberg vanagon and it has the stock tach in the dash
> pod. I will be parting out this vanagon and then off to the crusher but it
> has a tach that I want to know if it is just a straight swap to my 84 GL. My
> vanagon has a standard Clock. Will the harness already have the wiring for
> the tach to work??
>
> Jonce Fancher
> >
> You will need to bring a tach wire from the coil up to the dash console.  A
> standard 84 did not have this wiring.  Other than that, assuming the
> Wolfsberg did not do '85 or later type wiring, you should be good to go.  I
> would check the pinouts on your wolfsberg dash console vs. the vanagon to
> make certain there are no differences.  85's had, I think, one ground on
> different pins, so you should check for that.  Later models had major pinout
> differences.
>
> Rich
>