I finally get it. I found a wiring diagram at the GQF website. It works like a three way lighting circuit. Also, the turning arm cam is shaped so that it picks up its switch for 180 degs and releases it for the other 180 degrees.
https://www.gqfmfg.com/pdf/Wiring Diagram for 1502.pdf
https://www.gqfmfg.com/pdf/Wiring Diagram for 1502.pdf