Vic,  A wiring diagram for the Ametek Windjammer Blower can be found at
this location:

  http://organ.10.forumer.com/viewtopic.php?t=1100&highlight=ametek 

and scroll down to my posting with the wiring diagram.

There are two types of Windjammer: one with the potentiometer only
and one with the internal pot and external control wires.  The internal
pot is in series with the wires which go to the external connector.
I connected a 10K multi-turn pot as a potential divider between 0 and
10V and the wiper of this pot goes to the 'High' input on the connector.
The 'Low' input goes to the 0 volts side of the 10-volt supply.

Hope this helps,
Stephen Brickles