HVAC System - Control Components: Other Ford Expedition II

Manual Climate Control

The manual climate control components are used to select

1. Air inlet source (outside or recirculated).
2. Blower motor speed.
3. Discharge air temperature (temperature blend).
4. Discharge air location (defrost, panel, floor).
5. A/C compressor operation.

Scheme 187

Function Selector Switch

The function selector switch combines a vacuum selector valve that determines air distribution and an electrical switch to supply battery voltage to the A/C compressor circuit and the blower motor circuit. When the function selector switch is in the MAX A/C, DEFROST or FLOOR/DEFROST positions, the A/C compressor will be operational regardless of the A/C request switch status.

Blower Motor Switch

The blower motor switch controls blower motor speed by supplying voltage to the blower resistor circuits.

Blower Motor Resistor

The blower motor resistor

1. Is located on the plenum chamber near the blower motor.
2. Has three resistor elements mounted on the resistor board to provide four blower motor speeds.
3. Has an overheating device (thermal limiter) that will open the resistor coil when the temperature reaches approximately 184°C (363°F), interrupting the blower motor operation in all speeds except high.
4. Is serviced as an assembly. The thermal limiter cannot be reset and is not serviceable.

Depending on the blower motor switch position, series resistance is added or bypassed in the blower motor circuit to decrease or increase blower motor speed.

Temperature Blend Door Actuator

The temperature blend door actuator

1. Is located on the plenum chamber.
2. Moves the temperature blend door on command of the temperature control switch.
3. Contains a reversible electric motor.

Vacuum Control Motors

The three vacuum control motors have the following characteristics

1. They are actuated by the function selector switch.
2. They position the plenum doors to direct system airflow to the vehicle interior as determined by the function selector switch settings.
3. The air inlet door vacuum control motor is a single-diaphragm actuator with a single vacuum source.
4. The airflow mode door vacuum control motors are double-diaphragm actuators with two separate vacuum sources to allow the actuator to fully retract or partially retract.
5. When vacuum is applied to both vacuum sources, the actuator will fully retract.
6. When vacuum is applied only to the partial stage vacuum source, the actuator will partially retract.

Coolant Control Valve

The coolant control valve is actuated by the air inlet vacuum circuit. When the air inlet vacuum circuit is closed (at full vacuum), coolant flow through the heater core is shut off and A/C cooling efficiency is increased.

Dual Automatic Temperature Control

The dual automatic temperature control (DATC) module analyzes input from the following major sources

1. Temperature, function and blower selection (made by the vehicle occupants)
2. In-vehicle temperature
3. In-vehicle humidity (Navigator only)
4. Ambient temperature
5. Sunload
6. Vehicle speed
7. Engine coolant temperature

Using these inputs, the DATC module determines the correct conditions for the following outputs

1. A/C compressor operation
2. Blower speed
3. LH side temperature blend door position
4. RH side temperature blend door position
5. Panel airflow door position
6. Airflow door positions
7. Coolant control valve

Scheme 188

Steering Wheel Audio/Climate Control Switch

The steering wheel audio/climate control switch

1. Is located on the right side of the steering wheel.
2. Allows the driver to adjust the passenger compartment temperature setting and manually override the blower motor speed setting.

For removal and installation of the steering wheel audio/climate control switch, refer to AUDIO UNIT .

Ambient Air Temperature Sensor

The ambient air temperature sensor

1. Is located in front of the condenser core.
2. Provides a resistance value to a reference voltage from the DATC module that is proportional to the outside ambient temperature. The resulting voltage is then returned to the DATC module where it is interpreted as a temperature reading.

In-Vehicle Temperature/Humidity Sensor - Navigator

The in-vehicle temperature/humidity sensor operates in the following manner

1. A thermistor in the in-vehicle temperature/humidity sensor measures air temperature inside the passenger compartment.
2. A humidity transducer in the in-vehicle temperature/humidity sensor measures in-vehicle humidity.
3. A hose and elbow is connected between the plenum chamber and the in-car temperature/humidity sensor.
4. Airflow through the plenum chamber creates a venturi-type suction through the hose which draws passenger compartment air through the in-vehicle temperature/humidity sensor and across the thermistor and humidity transducer.

In-Vehicle Temperature/Sensor - Expedition

The in-vehicle temperature sensor operates in the following manner

1. A thermistor in the in-vehicle temperature sensor measures air temperature inside the passenger compartment.
2. A hose and elbow is connected between the plenum chamber and the in-vehicle temperature sensor.
3. Airflow through the plenum chamber creates a venturi-type suction through the hose which draws passenger compartment air through the in-vehicle temperature sensor and across the thermistor.

Dual-Zone Solar Amplifier (Sunload Sensor) - Navigator

The solar amplifier is a dual-zone type that supplies separate information to the DATC module indicating LH side and RH side sunload. For information on the location and service of the solar amplifier, refer to EXTERIOR LIGHTING .

Single-Zone Solar Amplifier (Sunload Sensor) - Expedition

The solar amplifier supplies information to the DATC module indicating sunload. For information on the location and service of the solar amplifier, refer to EXTERIOR LIGHTING .

Automatic Temperature Control (ATC) Solenoid and Manifold

The ATC solenoid and manifold

1. Is located on the plenum chamber in front of the front floor console.
2. Is controlled by the DATC module.
3. Uses solenoid-type valves to distribute manifold vacuum to the vacuum control motors based on the settings of the DATC module.

Blower Motor Speed Control

The motor blower speed control

1. Is located on the heater core and evaporator core housing near the blower motor.
2. Converts low power signals from the DATC module to a high current, variable ground feed for the blower motor.
3. Varies the blower motor speed and is controlled by the DATC module software.
4. Has a delay function to provide a gradual increase or decrease in blower motor speed under all conditions.
5. Controls the integral high blower speed relay which is engaged when maximum fan speed is selected.

Temperature Blend Door Actuators

The DATC system utilizes two temperature blend door actuators to control two separate temperature blend doors that independently vary the LH and RH side temperature settings, as desired. The temperature blend door actuators

1. Are located on the plenum chamber.
2. Move the temperature blend doors on command from the DATC module.
3. Contain a reversible electric motor and a potentiometer. The potentiometer wiper is connected to the actuator output shaft and moves with the output shaft to indicate the position of the temperature blend door.
4. Receive a reference voltage to one end of the potentiometer. The voltage available at the wiper indicates the position of the potentiometer. The expressed value of the actuator wiper voltage is sent to the DATC module and is matched with an expected wiper voltage value. The DATC module then drives the actuator motor in whichever direction is necessary to make the actuator wiper voltage match the expected DATC module wiper voltage value.

The three vacuum control motors have the following characteristics

1. They are actuated by the ATC solenoid and manifold based on input from the DATC module.
2. They position the mode doors to direct system airflow to the vehicle interior as determined by the DATC module settings.
3. The air inlet door vacuum control motor is a single-diaphragm actuator with a single vacuum source.
4. The airflow mode door vacuum control motors are double-diaphragm actuators with two separate vacuum sources to allow the actuator to fully retract or partially retract.
5. When vacuum is applied to both vacuum sources, the actuator will fully retract.
6. When vacuum is applied only to the partial stage vacuum source, the actuator will partially retract.

The coolant control valve is actuated by the coolant control valve vacuum circuit. When the coolant control valve is closed (at full vacuum), coolant flow through the heater core is shut off and A/C cooling efficiency is increased.

Refer to CLIMATE CONTROL SYSTEM-GENERAL INFORMATION .

Scheme 189

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Scheme 194

1. Disconnect the negative battery cable.
2. Detach and position aside the switch housing.
3. Detach the shift lever cover. Disconnect the electrical connector.
4. Remove the center console trim panel. Remove the screws. Disengage the four clips. Remove the center console trim panel.
5. Disconnect the electrical connectors and remove the screws.
6. Remove the center instrument panel finish panel. Open the audio unit cover to the full open position. Disengage the four clips. Disconnect the electrical connectors.
7. Apply the parking brake and place the gear selector in (1).
8. Disconnect the negative battery cable.
9. Remove the screws and the instrument cluster finish panel. Disconnect the electrical connectors.
10. Remove the screws and the climate control assembly.
11. To install, reverse the removal procedure.

Scheme 195

Scheme 196

1. Remove the screws and the instrument cluster finish panel. Disconnect the electrical connectors.
2. Remove the screws and the climate control assembly.
3. To install, reverse the removal procedure.

Scheme 197

1. Remove the manual climate control assembly. For additional information, refer to «CLIMATE CONTROL ASSEMBLY -MANUAL»(ref-209927-S20326299762005121200000) .
2. Pull and remove the function selector knob.
3. Release the clips and remove the function selector switch.
4. To install, reverse the removal procedure.

Scheme 198

1. Remove the climate control assembly. For additional information, refer to «CLIMATE CONTROL ASSEMBLY -MANUAL»(ref-209927-S20326299762005121200000) .
2. Pull and remove the blower motor switch knob.
3. Release the clips and remove the blower motor switch.
4. To install, reverse the removal procedure.

Scheme 199

Scheme 200

Scheme 201

1. Remove the radiator sight shield. Remove the pin-type retainers. Remove the radiator sight shield.
2. Detach the ambient temperature sensor pin-type retainer.
3. Disconnect the electrical connector and remove the ambient temperature sensor.
4. To install, reverse the removal procedure.

Scheme 202

Scheme 203

Scheme 204

1. Remove the screws and the instrument cluster finish panel. Disconnect the electrical connectors.
2. Disconnect the aspirator hose and the in-vehicle temperature sensor electrical connector.
3. Remove the screws and the in-vehicle temperature sensor.
4. To install, reverse the removal procedure.

Scheme 205

Scheme 206

Scheme 207

1. Remove the in-vehicle temperature and humidity sensor trim cover.
2. Disconnect the aspirator hose and the in-vehicle temperature and humidity sensor electrical connector.
3. Remove the screws and the in-vehicle temperature and humidity sensor.
4. To install, reverse the removal procedure.

Scheme 208

1. Remove the instrument panel. For additional information, refer to «INSTRUMENT PANEL AND CONSOLE»(ref-209958) .
2. Remove the temperature blend door actuator. Disconnect the temperature blend door actuator electrical connector. Remove the screws. Remove the temperature blend door actuator.
3. To install, reverse the removal procedure.

Scheme 209

Scheme 210

1. Remove the plenum chamber. For additional information, refer to «AIR DISTRIBUTION & FILTERING»(ref-209922) .
2. Remove the screws and the floor duct.
3. Remove the temperature blend door actuator. Disconnect the temperature blend door actuator electrical connector. Remove the screws. Remove the temperature blend door actuator.
4. To install, reverse the removal procedure.

Scheme 211

1. Remove the RH lower instrument panel insulator.
2. Remove the blower motor speed control. Remove the screw. Remove the blower motor speed control. Disconnect the blower motor speed control electrical connector.
3. To install, reverse the removal procedure.

Scheme 212

Scheme 213

1. Remove the bolts and position aside the accelerator pedal.
2. Remove the floor/defrost door vacuum control motor. Disconnect the vacuum connector. Remove the screws. Rotate the floor/defrost door vacuum control motor to clear the retaining arm.
3. Remove the floor/defrost door vacuum control motor.
4. To install, reverse the removal procedure.

Scheme 214

1. Remove the instrument panel. For additional information, refer to «INSTRUMENT PANEL AND CONSOLE»(ref-209958) .
2. Remove the panel door vacuum control motor. Disconnect the vacuum connector. Remove the screws. Rotate the panel door vacuum control motor to clear the retaining arm. Remove the panel door vacuum control motor.
3. To install, reverse the removal procedure.

Scheme 215

Scheme 216

1. Remove the instrument panel. For additional information, refer to «INSTRUMENT PANEL AND CONSOLE»(ref-209958) .
2. Disconnect the vacuum connector.
3. Remove the screws and the air inlet door vacuum control motor.
4. To install, reverse the removal procedure.

Scheme 217

1. Remove the battery and battery tray. For additional information, refer to «BATTERY, MOUNTING AND CABLES»(ref-209935) .
2. Disconnect the vacuum hose and remove the vacuum reservoir.
3. To install, reverse the removal procedure.

Scheme 218

Scheme 219

Scheme 220

1. Remove the floor console trim panel.
2. Remove the bolts and the instrument panel brace.
3. Remove the automatic temperature control (ATC) solenoid and manifold. Disconnect the vacuum and electrical connectors. Remove the screw. Remove the ATC solenoid and manifold.
4. To install, reverse the removal procedure.