I am curious what the difference is between ac and ac max, I can adjust the fan speed on eather, Is one recirc air (max) and the other, cooling outside air (ac),,, No matter which i choose, I still get 42-50* air with a 90+* outside temp.
Peter.

 

Max is recirc.

 

A/C Max shifts the recirc damper that is located on the passenger side right in front of the little grill near the floor in the cab to full recirc. It also closes the heater control valve preventing hot water from flowing through the heater core. A/C is fresh air supplied and it gives you temperature control with the heater control lever.