Dash Air Conditioning

Automotive air conditioners use a cool-reheat system where the air is cooled by the air conditioner and then warmed to a comfortable temp if full cooling is not required. It can even be heated to an elevated temp for de-fogging the windshield. If the reheat function is not shutting off properly it can make your airconditioner useless. Turn your system to "Vent" and the temp all the way down and see if the output air is warmer than the air coming in. If so, you have a heater control problem. Some Fords have a valve in the hot water line supplying the heater that is supposed to shut when no heat is asked for. If that valve leaks your air will be warmed somewhat, how much depends on the leak rate. My father had a Ranger with that problem new. The dealer's mechanics had no clue how the system worked or what that valve did. He finally replaced the valve himself and solved the same symptons that you are describing.

Good Luck.