I asked Boston Bob about this sensor when I replaced my engine last summer.

That wire is the TDC sensor next to the flywheel. They are difficult to get
out
without actually hammering them out from the other side..

[ engine removed]

I am told that no one ever uses the TDC sensor and the diagnostic
tools to access it are pretty long gone from the dealers.

-hence my rebuilt engine came with cut off one used just to plug the hole in
the case.

Tom

        ----------
        From:   Dan Barrett
        Reply To:       Dan Barrett
        Sent:   Wednesday, July 9, 2003 12:28 AM
        To:     vanagon@GERRY.VANAGON.COM
        Subject:        wire from alternator to front of case 2.1L

        Volks,
        Can anyone tell me how to disconnect the wire that runs from the
alternator to
        the front end of the engine case (where it bolts to the tranny)?
The
        connection is covered in a small rubber boot -- do I pull straight
out?
        Twist?  I've given it a good couple of yanks with a pair of pliers,
but no
        dice.

        Many thanks,
        d.
        1990 GL -- "Mudskipper"