Checked the unit. Fed 12 volt directly it works, both ways.
I believe the blue wheel is connected to some kind of potentiometer for position recognition. May that be where the problem is?
If I go around the darn thing and istall a reversible feed control, would that work?
What would I lose?

 

see the five pins...3 are for a position sensor...5 volt referenc, signal and grd.. the other 2 are power and grd for the motor. why not swap in one of the other door actuators...the blend, recirc and mode door actuators should all be the same.

 

Again I'm late with an answer. I'm just heaped over with work and other obligations.
This truck is on stand by at the moment, awaiting winter, or something. Drive my Cadillac instead, AC working.

Not sure where to find the other connections to swap with. I am really not good with electric - electronic stuff.
I can measure on the connector I loosened to remove the door actuator. But what should I read and between what pins, or grund?