Yeah, if you look through the wiring diagrams, there is a 12v clutch which you can apply power to, and it will engage / dis-engage. There are also 2 sensors if I remember correctly. The speed sensor which Luke mentioned, and possibly a pressure sensor somewhere. When I had my AC problems, I kept getting a Speed Sensor error on the AC diagnostics. My problem ended up being the Speed Sensor pin in the back of the AC unit harness had been pushed back. Connected it back up and the unit was working again/