You won't see power at that connection until the alternator starts charging.
At rest that connection provides a ground path (through the regulator and
rotor) and with power on the other side of the light ( with some other
stuff) turns the light on. That current is what helps the alternator get
"started". Once the alternator is producing current the voltage at that
terminal cancels out the  voltage on the other side of the light causing the
light to turn off.

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Gene P
Sent: Monday, July 09, 2012 5:36 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Alternator blue wire

87 Wolfsburg
Runs fine, but battery & OXS lights on all the time = blue alt wire issue,
right?
But never mind the wire, there is no power to the spade terminal on the
alternator that blue wire attaches to -- key on or engine running, no power
to that terminal.

Is there a better answer than alt gone over the hill?