Pictures are a little hard to see, but it sure looks like it goes to a
sensor that's triggered by the flywheel, for use with dealer-used diagnostic
equipment.
 Normally it's bolted in a clamp the one of the alternator housing securing
screws.  You can leave it hanging, or bust it right out of the engine case
if you like. I doubt it'll ever get used. Scott
www.turbovans.com 

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Jim Johnston
Sent: Monday, November 26, 2007 3:46 PM
To: vanagon@GERRY.VANAGON.COM
Subject: what is this wire...?

Hello all,

I'm in the process if replacing a few things, namely a broken alternator
bracket, breather O-ring, and a cracked intake manifold hose.  In the
process, I found a mystery wire.  It has three wires, one regular, and a
couple of prongs.   It leads to a plug or sensor that is below the intake
manifold, behind the throttle body.  I have no idea where or what this was
plugged into.

The van in question is a 1991 Vanagon GL with a Manual Transmission.

Here are some pictures.  http://picasaweb.google.com/inmytree1/MysteryWire

Thanks,
Jim
Wilmington, NC