Chrysler Repair: climate control air conditioner, motor actuator, chrysler new yorker

Question
I have a 1988 Chrysler New Yorker with an AC blend door malfunction.  The door opens randomly during AC use and the unit blows hot air and vice versa during heater use.  Diagnostics show an 02 code for motor actuator; however, the code shows intermittently and replacement of the motor did not solve the problem.  Any ideas?

Answer
Hi Mark,
If the door isn't binding up then it could be the wiring or the ATC control unit. So check for binding.
Here are the pins of the four wires to the actuator:
ATC control  16-way disconnect  Actuator
17                 11               3
18                 13               1
8                 15               4
7                 14               5
If those wires prove continuous, reconnect the plugs and:
Set the ATC control to 85 and wait for at least 30 seconds. Connect a voltmeter to pin 8 of the ATC control. Adjust the temperature to 85, wait for at least 30 seconds. Then change the temp setting to 65 and monitor the voltage. The voltage should change slowly from its present level to less than 1.0V. If it reaches this point and an 02 code was issued replace the ATC control. If the voltage value was not reached, then replace the actuator and retest. If error code persists replace the ATC control.  
Roland