| Description and Operation The heating system is a blended air system and consists of the heater core, the blower motor, distribution doors and an evaporator core on vehicles equipped with air conditioning (A/C). Air is directed through the heater core for heating and around for cooling, mixed and discharged through outlets in the plenum assembly to the floor, instrument panel or defrost nozzles, as required. For additional information, refer to Section 412-01 Air Distribution and Filtering. Heater Core Housing In the heater core housing, the air inlet blend door is actuated electronically by means of a control motor. Vehicles with automatic air conditioning (Climatronic) have an additional center register blend door actuator, which is also actuated electronically by means of a control motor. | Item | Description | | 1 | Temperature blend door actuator | | 2 | Air inlet blend door actuator | | 3 | Blower motor | | 4 | Blower motor resistor | | 5 | Evaporator outlet air temperature sensor | | 6 | Defrost vent/footwell vent blend door actuator | | 7 | Center register blend door actuator (only Climatronic) | | 