How do I get my Hotpoint Aquarius 900 drum to move during cycle?

My Aquarius 900 WM61 drum will not churn / rotate during cycle.
Cycle moves through, and internal switch "clicks on and off" during time when drum should be turning, and when it should spin but zero movement. Drum belt is in place. Machine fills and pumps away at appropriate times. Drum is free moving when machine is off.