Good. this should look familiar to you then:
The yellowish plastic part is the air mix door lever (for lack of a better term). This lever should point to the driver'* B pillar for full cold and to the passenger'* B pillar for full hot. When you adjust from full hot to full cold the lever should travel smoothly without stoping or pausing for the full 90* swing. The actuator may not be allowing the door to fully open and close but is allowing some movement in between.
In this pic, the lever is very close to the full hot position:
This one, the lever is in the full cold position: