Heater Core
WARNING: This page is about a different car, the 2003 Ford Pickup, 2003 Ford F550 Super Duty, 2003 Ford F450 Super Duty, and 2003 Ford Excursion. However, it is still accessible from the selected car via links, so may be relevant.
The auxiliary A/C system uses a rear heater core which operates in the same manner as the front heater core. Refer to HEATING & VENTILATION .