If the heat is on that would explain it. But if you are running the air conditioning, the compressor is on and fully charged with r134 it is probably the air mix door inside the heater stuck in heat mode.
You have a broken vacuum hose under the hood that supplies the switch.
The steam could be coolant from a bad heater core.
Of course it affects the air conditioning,,,it also affects the heater. Any time u have a restricted air flow it affects how heater and air conditioning works, for the worse. Engineers have designed the heater/ac system to run on clean air, so therefore your heater/ac systems work faster and better with a clean filter. Not to mention your own physical health by breathing clean air.
For both your heater and air conditioning not to work means you either broke a belt or the belt is loose. Overheating would also be caused by this, because your water pump is driven by the same belt. Do not drive it until you get it fixed, you'll kill that engine by overheating it.
air conditioning and heater control
Maybe its broken. Or maybe you pressed the AIR CONDITIONING
Disconnect the negative battery cable.Discharge and recover the air conditioning system refrigerant.Disconnect the refrigerant lines from the evaporator. Plug the openings to prevent contamination.Disconnect the refrigerant lines from the accumulator. Plug the openings to prevent contamination.Remove the accumulator.Drain the cooling system into a clean container for reuse.Disconnect the heater hoses from the heater core tubes.Remove the PCM from the dash panel and move it aside. Do not disconnect the PCM harness connector.In the engine compartment, remove the heater/air conditioning housing assembly-to-chassis nuts.In the passenger-s compartment, remove the heater/air conditioning housing-to-dash panel nuts.Pull the heater/air conditioning housing assembly rearward far enough to clear the studs and air conditioning drain tube holes.Remove the heater/air conditioning housing assembly from the vehicle.Remove the upper-to-lower heater/air conditioning housing screws and remove the upper housing.Remove the heater core from the lower housing.
you could have an air pocket in your core. the speakers check fuse.
Owner of a 2002 Concorde - car has no cabin filter - aka air conditioning filter
Discharge and recover the air conditioning system refrigerant.Disconnect the refrigerant lines from the evaporator. Plug the openings to prevent contamination.Disconnect the refrigerant lines from the accumulator. Plug the openings to prevent contamination.Remove the accumulator.Drain the cooling system into a clean container for reuse.Disconnect the heater hoses from the heater core tubes.Remove the PCM from the dash panel and move it aside. Do not disconnect the PCM harness connector.In the engine compartment, remove the heater/air conditioning housing assembly-to-chassis nuts.In the passenger-s compartment, remove the heater/air conditioning housing-to-dash panel nuts.Pull the heater/air conditioning housing assembly rearward far enough to clear the studs and air conditioning drain tube holes.Remove the heater/air conditioning housing assembly from the vehicle.Remove the upper-to-lower heater/air conditioning housing screws and remove the upper housing.Remove the evaportor core from the lower housing.
no , the heater core is for your heat , the evaporator core is for your air conditioning ( cooling )