Actually there are two little pins in the flywheel. The three wire
connector is connected to a hall sensor that is powered through the three
wire connector, it blinks a light at TDC. I don't know of any body that
ever rigged a devise to use the thing.
Most people find TDC once and mark it on the fan/shroud and the TDC
sensor isn't required. It is nice to have the hole plugged.

Stan Wilder
83 Air Cooled Westfalia

On Wed, 29 Aug 2001 22:39:54 -0300 Jean-Guy Savoie <jgsavoie@NBNET.NB.CA>
writes:
> Hi,
>
> My understanding, correct me if I'm wrong, is that there is a small
> magnet
> on the flywheel so that the 3 pronged connector would only blip once
> per
> revolution.  Apparently you can feel this magnet on the flywheel
> through the
> little hole on the housing.  When it is perfectly lined up
> vertically, you
> are at TDC for #1 cylinder.
>
> JGS
>
> 84 1.9L Westfalia
> Bleu Schtroumpf
>
>
>
> ----- Original Message -----
> From: Bradley Flubacher <flubach@HOME.COM>
> To: <vanagon@GERRY.VANAGON.COM>
> Sent: Wednesday, August 29, 2001 10:05 PM
> Subject: Re: 3 prong connector on alternator
>
>
> > I have a strong suspicion that you could simply hook up +12v on
> one lead,
> > ground on another, and a freq meter on the other and acheive the
> same
> > thing...  if not 12v,  something... undoubtedly just an optical
> something
> or
> > other that blips for each flywheel tooth that passes by it... Some
> day
> when
> > I have too much spare time I'll probably wind up rigging something
> there...
> > Anyone know how many teeth are on the flywheel?
> >
> >
> >
> > Bradley Flubacher
> > State College, PA
> > '82 VW diesel westy
> > '84 GL wasserboxer
> >
> > -----Original Message-----
> > From: Vanagon Mailing List [mailto:vanagon@GERRY.VANAGON.COM]On
> Behalf
> > Of All of Us
> > Sent: Wednesday, August 29, 2001 6:10 PM
> > To: vanagon@GERRY.VANAGON.COM
> > Subject: Re: 3 prong connector on alternator
> >
> >
> > Volks:
> >
> > That connector is one of the points where your friendly VW
> technician will
> > plug one of the leads on their very expensive ($2,800.00 last time
> I
> > checked) special tool for checking the timing on your Digifant
> Vanagon.
> That
> > is if the dealer even has special tool number 1367.
> >
> > If you have a Bentley laying around (and you should, by the way)
> you can
> > look in section 28.42 to see what gets hooked where and how it all
> works.
> > Good luck and let us know if you find any other mysteries.
> >
> > Dan Weber
> > Miss Blue - "87 GL Weekender
> >
> > ----- Original Message -----
> > From: Fitz-Randolph, Douglas <Doug@BEACONMARKETING.NET>
> > To: <vanagon@GERRY.VANAGON.COM>
> > Sent: Wednesday, August 29, 2001 3:49 PM
> > Subject: Re: 3 prong connector on alternator
> >
> >
> > > Yeah... I've got that too - 90 2.1 - kinda
> > > mysterious to me as well.
> > >
> > > > Doug Fitz-Randolph
> > > > Freeport, ME
> > > > '90 Syncro
> > >
> >

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