Ford Repair: 97 Ford Ranger A/C, electric actuator, heater settings

Question
I have a 97 Ranger 4-cyl. The A/C blows hot air on all settings. The freon levels have been checked and are good. The compressor engages even when set on the heater settings. Approximately 3 months ago, the problem started except when set to Max A/C. However, after needing to use the defroster, its been blowing hot air on all settings.  

Answer
I am pretty certain your problem is in the blend door area. It is a common failure on Rangers and Explorers. There is an electric actuator for this door, sometimes the actuator stops working, but more commonly the blend door itself breaks where the actuator turns the door. Repair can be accomplished by replacing the door, but I prefer to replace the plenum which includes a stronger, redesigned door. Labor time will be the biggest expense, unless you can do it yourself. Requires removal of the instrument panel.