2012 Caravan with dual climate controls. Manual ***** on control unit. not the digital display one. I have replaced the top blend door in the back twice now (repaired, bought a new one and then swapped it out with one from another location) and they ALL 'hunt' or calibrate for a minimum of 1 minute. I counted once, the rear cycled 13 times before the A/C finally clicked on! These actuators moan at the stress of trying to move past their stops as they only travel <90 degrees. Ford uses the same actuators but they use a rheostat inside (high failure point too!) that determines the position of the door with 5 pins, Mopar uses only 2 pins. How does it know where the door is or does it cycle all 4 or 5 on start and then possibly use a duty cycle timer to determine when to cut power when they reach their limits? Does the PCM use the draw of a bound motor to stop its power? Do I have a faulty A/C control panel? Its almost comical to listen to all these actuators move around when you get in a 120F interior with the engine running and A/C turned on...This top actuator was replaced with an Amazon replacement AND it was swapped out with the lower OEM one thinking the gear ratio was different and it was moving faster that the OEM one. No wonder these break teeth and shear axle pins inside, there is no mechanism to stop these when they are at their full swing! Only the possible amp draw of the motors or maybe a timer, or possibly a stepper motor control via the PCM without a hall sensor on the motors themselves? Im ready to gram another A/C control panel off a wreck at my local pick-a-part as they get 1-2 a week now. :-(

 

found out the current spike is the trigger to stop the actuator and mark it as "end of travel" then it goes the other way and does the same thing. Should only do it once and then be done. I assume the bi-directional scan tool calibration feature will do this and set all the actuator stop points. I just dont have that bi direction scan tool yet. and my super blu-tooth dongle phone contraption does not have this function.