Was your car built before July 22, 2005?
Did they see this TSB?
http://www.wkjeeps.com/misc/LX/TSB/TSB_2401205a.pdf
SYMPTOM/CONDITION:
The vehicle operator notices a loss of airflow from the vents and becomes uncomfortably warm after a long drive in hot and humid weather while operating with the air conditioning on. The A/C evaporator is freezing up. Ice forms on the evaporator and blocks airflow into the cabin.