Ahhh, this happened to me. There is a TSB(technical service bulletin) out for this problem. Also, I would caution taking this TSB to your dealer and telling them to fix it. Approach the subject stating you think your car is experiencing a problem that sounds like a recent TSB. They are much more receptive to this approach than cramming a copy of the TSB in their face. However, here's the TSB:
A/C - Lack of Cooling From Driver/Passenger Vents
Article No.
03-3-4
02/17/03
CLIMATE CONTROL - LACK OF COOLING FROM
DRIVER AND/OR PASSENGER SIDE VENT -
VEHICLES EQUIPPED WITH DUAL AUTOMATIC
TEMPERATURE CONTROL (DATC) ONLY
FORD:
2002 THUNDERBIRD
LINCOLN:
2000-2002 LS
Article 00-15-3 is being republished in its entirety to update the models covered and to update the Basic Causal Part number.
ISSUE
Some vehicles may exhibit a lack of A/C cooling from either the driver or passenger side vents or an extreme temperature difference between the driver and passenger side on vehicles with DATC (Dual Automatic Temperature Control): This may be caused by a faulty DCCV (Dual Coolant Control Valve), a faulty DATC control assembly, or faulty electrical circuits.
ACTION
Inspect and service as necessary, electrical circuits, DCCV and DATC control assembly. Refer to the following Service Procedure to aid in diagnosis and repair.