Automatic temp control

[guest]

2011 Chrysler 300C
Automatic temp control works well on hot days, fan speed adjusts properly as needed.
Actuators open/close properly under manual control as does fan.
On cold days system sets fan speed on low and will not increase to properly warm the car. Little or no air to rear so rear seat is cold and rear window fogs. On defrost system starts high but drops speed before window clears. Outside temp display is correct. To get higher speed the temp must be set a max and then the system is still not properly setting fan speed. Cabin filter is new.

[carriedi]

you might want to have the dealer scan to see if there are tsb's that are contributing to your problem. OEM ref# 24-014-16 is for FLASH HVAC SYSTEM ENHANCEMENT and OEM ref# 24-002-14 DRIVER AND PASSENGER AIR TEMPERATURE ARE NOT THE SAME WHEN IN "SYNC" SETTING IS SELECTED AND THE HEADLIGHTS ALWAYS STAY ON

Or, having a good scanner look at the HVAC control module and see if there are any codes of check the PIDs and see if they are matching to the controls. The control module may be affected by the weather and messing up. If you can look to see if the module is matching the requests from the dials