My main focus right now is how the auto a/c controls the blower motor speed....Thanks in advance

 

I don't know, but my observation is that it ramps up the blower speed as the cabin temperature deviates more from the set temperature. The auto also tries to predict the cooling needed depending on the solar load, there's a sun sensor on the front of the dash. You can notice it changing its cooling strategy as you head into or away from the sun.

If the fan doesn't seem right to you, you can always override the auto setting. You can change the fan speed manually and it'll do its best to work with the fan speed you set. My wife likes to turn up the fan to get more airflow.

 

Thanks for the reply. Im actually trying to find out exactly how its wired though not the operation.

 

Talking out of my tailpipe, I'd say it's controlled via the BCM as it needs some smarts to figure out how fast to spin (aka resistance in the circuit.)

 

Nope. Looked at it today, the IHKA uses PWM controller to set the fan speed.

 

Do you have the wiring diagrams? They were on the TIS discs you could pick up for 2007- cars, and the Bentley manual has a lot of them.