My 1996 Lincoln Town car heater works but you cannot control the temperature and the air conditioner blows out hot air when turned on.What could be the cause of this problem?

a belt or frion

Does this have the electronic/digital control panel ?

called a thermostat and it is under the dash next to the ac unit evaporator

likely a leaking heater core, the smell is likely antifreeze

Sounds like your Blend Door Actuator has gone and it isnt opening or shutting no more,

check the sensor in the dash near the controls looks like a tiny vent see if it has dust build up

Hi - There may be 2 separate problems. On my 1991 Lincoln Town Car, there is a Thermal Blower Lockout sensor that disables the heater from blowing until the engine temperature reaches a specific temperature. This way if you have vent or floor settings and 90 degrees set and it is winter, you won't get blasted with cold air. When the vehicle warms up, the TBL circuit enables the climate control to blow the hot air. If you use the flr/def instead of the floor or vent control, the TBL should not prevent the heater from working even with a cold engine. On my car, the TBL went bad and always prevented hot air from blowing on the floor and vent settings, even when the engine was hot. Another thing to check is a thermal limitor resistor. It is designed to cut off the blower at very hot temperatures, except if the blower fan is in the hi setting.

As far as the A/C is concerned, can you verify if the clutch is engaging or not? A rapid cycling of the clutch is an indication of low freon. If you are absolutely sure that you are fully charged on freon, I think there are 2 possible causes: (1) Bad pressure switch on the accumulator is indicating low freon that is telling the compressor not to work; (2) a blocked orifice tube.

Sounds like the heater and a/c blend door actuator. It is located under front center of dash below windshield. Dash must be removed to replace it. I've done it several times.

this sounds like a defective air temperature control sensor, it is located behind the glove box, problem is the part is most likely no longer availiable from Ford..

bad blower resistor