No heat but engine is warm on 2004 Ford Taurus

The door actuator that should move when you turn the heat dial does not move. There is warm water going to the heater core. I searched the Internet and I think I'm looking at the door actuator assy, it's white and has a lever that points down at an angle which I think is supposed to move with the dial. Am I on the right path to resolving this issue? Thanks!

Possibly so if you are seeing a motor attached at the plenum where the door sits.

Happily it seems as if this motor does not require dash removal, as it does on many other vehicles.