your friend is correct.
it's for dealer diagnostic equipment to plug into.

often that wire and connector are just  removed from the engine, since it's
never used anyway.
----- Original Message -----
From: "A PETER MARSH" <apetermarsh@MAC.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Tuesday, November 30, 2010 1:38 PM
Subject: Is this wire/socket any good?

> Learned Brethren,
>
> (I use the term loosely)
>
> Now I have stripped my "new" (used)  2.1 down to just about what it came
> with after it's VW Canada rebuild, there is one wire left attached to the
> case.  It has a small round socket with a couple of pins in it that
> fastens (on mine) to a convenient place on the side of the alternator.  A
> pal told me it is for a rev counter or some testing device they used at
> the factory.
>
> Can any one of the Brethren enlighten me further?
>
> TIA
>
> Peter Marsh