2005 Freestar Passenger rear side window motor won't stop

I have a 2005 Ford Freestar and the rear side power window has come loose from the motor/actuator arm. When I push the "close" button the drivers side window operates normally but the passenger side motor and arm just keep spinning and spinning. What tells the window motor to stop? It looks like the motor failed to stop and pulled the arm from the glass.

I live in the Seattle area and it will be raining for the next couple of months so I need to get this fixed soon.

Is the motor at fault? And once that gets figured out what type of adhesive should I use to reaffix the arm to the glass?

Thanks!