2002 ford explorer blower selection controls broken

Sounds llike vaccum problem with the heater 'doors' which switch directon of air flow.

If your a/c and heater vent doors are vacum controlled either a hose is off or is leaking and not closing the doors.

Check the duct work under dash might be unhooked

The most common cause is a bad blend door actuator which controls air flow throughout the cabin. When air flow only flows from 1 section (either floor, vent, or defrost) it's an indication that the blend door actuator is either stuck or broken.

Airflow goes into one main duct in dash and is redirected to the appropriate vents selected by the fan control switch on your dash. The shutter is controlled by cable attached to the back of the climate control unit. The problem, if the shutter or control switch, should be the same regardless of AC or Heat selection. The shutter is either stuck open or the cable has broken to control it. If the fan direction control switch is hard to turn and offers resistance or just the opposite it has too much free-play the cable is the culprit and is stuck or broken. If there is resistance it could be the shutter stuck and its within the dash. that is a bit more intricate to get fixed as you have to access the shutter by removing the dash.

You have a vent door broken in the blower box

It sounds like blower motor has failed. Motor is located behind glove box on lower part of heater box.

look for a broken plastic vacuum line under hood, vacuum is what controls the heater controls inside the car

check the coolant level & condition of antifreeze make sure it is not dirty/rusty/muddy if thats ok try a new thermostat & radiator cap if the antifreeze is muddy you may have to blow out the heater core

Sounds like your temperature actuator is not moving or your temp door is broken. On max a-c ,coolant is shut off to your heater core allowing only cold air in.