Are you able to take out the glove box liner? I have a feeling the actuator in question is in that area. Wish I knew for sure...sorry.
Also have you checked all vacuum lines under the dash?
With the engine off and key in the ignition in the acc on position......and fan on low speed....turn on the passenger side temp and move the temp up and down slowly. Listen for any movement behind the glove box.
Also do the same for the drivers side. Since you already know the drivers side works...listen how that side functions. Then compare the passenger side.
Report back when you can.
EDIT.......when listening on the passenger side...pay attention to any clicking sounds. If you here clicking, then that would be your typical broken actuator gear.
Although.....you have heat on the drivers side. Hmmmm.....yeah start with what was said already.
Last edited by Toddster; 02-07-2010 at 02:50 PM.