Chrysler Repair: cabin air flow: Pacifica, motor actuator, calibration procedure

Question
2005 Pacifica, air flow will not change from floor to dash. Flow will change to defrost vents when switch is depressed, fan slows and reduced air flow exist defrost ducts(don't know if it is correct volume). No change when the flow selector is moved from floor to dash ducts. Fan remains full, air continues high rate. I have checked connectors at blower all appears OK, but don't know if signal is getting from dash selector switch to blower unit. help

Answer
Hi Vern
I would begin by doing a 'calibration' of the unit. Turn the key to 'run', then press and hold for 5 seconds both the heater/ac power button and the reciruclation button. After about 5 seconds, depending upon which type of control you have there will be a procedure that the unit initiates and goes through a period of from 30 seconds to 2 minutes. Then see if the problem has self-corrected. If not, then probable the motor/actuator for the mode door has failed or otherwise is not functioning. If you remove the underdash panel on the driver side you will be able to look in and see the left hand side of the air distribution housing. You will see three identicaal devices that are the actuators of the mode/blend/recirculation doors. There are two forward and one aft. The upper foward actuator is the mode door actuator and it is responsible for moving the air distribution as requested. You can exchange the actuators with one another as they are identical. You could check the wiring on the mode door actuator and try switching it with another unit. If you do any switching then do the self-calibration procedure again. The actuators are held in by 2 screws. You may be able to observe them to move in response to requests that you make for distribution/temperature/recirculation changes.
That is the basic design of the system as far as your problem is concerned.
Roland
PS Sorry for the delay but I just found your question in the 'pool' to which it had been referred by the other expert. Please 'rate' my answer, and where you see the question about 'volunteer of the month' please consider giving a 'yes' answer. Thanks