Air conditioner/heat The air and heat will only come out of the defroster and nothing else. The back seat panels work too.

i'd think that the vent adjuster knob/slider is not working correctly strip out the heater panel around the control knobs and check the vent direction is working properly either stiff operation so a little wd40 on the cable would probably do the trick or some thing causing the vent itself to not move

Check you fuses and if that doesn't work check the connections on your fuse panel.

if you mean no air is blowing,i'd say your blower motors cooked or heater panel blower switch/or blower resistor may have melted

replace the panel control or heat control valve

If you are getting heat inside the car, the defroster should also work. There is a control switch problem that doesn't switch to defrost from heat, or the compressor for the air conditioner is not functioning...it provides heat for defrosting as very dry air to the heater box.

need a new AC computer

the blendor actuators strip out the gear inside the actuator cases on these all the time. replace the actuator.

I would think the door you hear flapping is the door that controls the airflow across the heater coil - and the fan keeps blowing the door closed, preventing the airflow from going across the heating coil. I don't know whether this vehicle is vacum controlled or cable controlled - so either it's a disconnected cable, or a leaking vacum line.

It sounds silly but there is a separate unit in your console that you can only turn off if you go in from back seats. You probably already did that, but if not try. You can not turn it off from any controls on front panel. If it doesn't work, I would think something is wrong with the switch. Open it up and look at wire connection from switch regulator. It also has a heat regulator on the console facing back seats? Mine does anyways.

replace the control unit.