Originally Posted by lash
your problem is either:
...1. Failed Airmix Actuator (probably a broken drive gear in the acuator).
2. A binding airmix door (haven''t heard of one yet, it is usually the actgator gear) ...
You have the classic symptoms of a cracked 'gator gear. For some reason it starts to manifest itself after a battery disconnection.
When you watch your actuator you'll probably see the programmer try to calibrate...it will attmept to drive the door full cold (to the left of the car), then full hot (right), then it will settle in someplace between based on the temperature setting. Set your temp to max heat and watch the action. Set it to max cool & watch. If you see any hesitation at all during movement, the actuator gear is slipping on the shaft.
Let us know what you see.