Hot, Cold Air Diverter Door Actuator or Dash Switch??

Seems like lately the temperature switch in my '00 Silverado is either all cold air or it tends to put out max hot air. Like there's no in between. If I rapidly rotate the switch back and forth, it'll eventually respond. In order to shut the hot air off for AC for example, I almost have to "slam" the switch all the way to the left on the cold setting. You get the hottest hot air you can get just barely in the red. Almost like the rheostadt has lost its scale.

On the other hand I've heard that the air diverter door actuator can hang up and/or become unresponsive causing a similiar problem.

In most cases is it the switch or the actuator?

Can anyone tell me where the actuator is located and what's involved in changing it?

I believe you have to buy the whole switch panel to replace/correct the air temp. switch if that's bad.

Thanks, V1