There is a heating element in the valve. This is what the power is for. The heating element causes the bi-metalic spring to change length and close the blade valve shutting off the air that is bypassing the throttle body.
The valve gets crudded up inside from the crank case fumes and vapor being sucked into the intake from the oil filler.
The breaks usually are at the wire side of the pins on the connector.
Pelican has the electrical diagrams for the early 944's.
http://www.pelicanparts.com/944/electrical/944_electrical_diagrams.htm
This is the page you need to study.
Lines 28 and 29.