While the heat selector cable was disconnected, I unhooked the connectors, removed the light, and pulled out the control unit. (picture 1).
The fan switch (picture 2) is a simple matter of one screw, then it slides out.
The vacuum valve is held by 2 screws, picture 3 shows the bottom view, picture 4 shows it from the top.
Picture 5 shows the vacuum connector, there are 2 long legs with push nuts that hold it in place. The vac selector CAN be changed without pulling the controller, but it ain't easy.
