Possible Causes

WARNING: This page is about a different car, the 2002 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.

Open fuse No. 17 (15 amp), located in Battery Junction Box (BJB).
Open fuse 2 (5 amp), 7 (10 amp) or 9 (3 amp), located in Central Junction Box (CJB).
Circuitry short/open.
A/C clutch relay.
A/C cycling switch.
A/C system discharged/low charge.
Function selector switch.