fantastic fan problem

[Mel B.]

We've been getting ready to leave on a trip tomorrow and for the last few days I have had the Fantastic fan on. This morning I went out to our rig and the fan vent was closed and the black knob handle was spinning with the motor. It wouldn't stop so I turned the switch on the wall from Auto to off the motor stopped. When I turn to either "On" or "Auto" the motor turns on but the vent cover does not open and the knob doesn't stop turning. I'm thinking maybe something broke in the gear box?? Anyone have this problem before?

[Montana Man]

That doesn't sound very fantastic.