FORD MUSTANG 2003 Workshop Manual

7. Disconnect the spring lock coupling at the evaporator core.
zDiscard the O- ring seals.
8. Remove the condenser to evaporator line.
9. To install, reverse the removal procedure. zInstall new O- ring seals lubricated in clean PAG oil.
z Lubricate the refrigerant system with the correct amount of clean PAG oil. For additional
information, refer to Section 412 - 00 .
10. Evacuate, leak test and charge the refrigerant system. For additional information, refer to Section 412 - 00 . Klj . 2 ba
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Klj . 3 ba
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DESCRIPTION AND OPERATION
Control Components
Manual A/C
The climate control system heats or cools the vehicle interior depending on the function selector
position and the temperature selected. Function selector position determines heating or cooling and air
distribution. The temperature blend control setting determines air temperature.
The manual climate control components are used to:
zselect air inlet source (outside or recirculated).
z select blower motor speed.
z select discharge air temperature (temperature blend).
z select discharge air location (defrost, panel, floor).
z select A/C compressor clutch operation. Component Locations SECTION 412-
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Control System Inputs
Climate Control Assembly
The climate control assembly has three system controls:
zThe blower motor switch controls blower motor speed by adding or bypassing resistors in the
heater blower motor resistor.
z The temperature selection is accomplished with a manually- controlled blend door actuator that
controls positioning of the temperature blend door. Movement of the control knob (18519) from Item Part
Number Description
1 18A318 Vacuum control motor (panel/defrost door)
2 19988 Temperature blend door actuator cable
3 18A318 Vacuum control motor (air inlet door)
4 A/C vacuum reservoir tank and bracket (part of
18454)
5 18A318 Vacuum control motor (floor/panel door) Klj . 2 ba
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COOL (blue) to WARM (red) causes a corresponding movement on the air temperature control
door and determines the temperature that the system will maintain.
z The A/C heater function selector switch combines a vacuum selector valve for direct control of
the vacuum control motors and electrical input to the instrument control module.
Control System Outputs
Blower Motor Switch Resistor
The heater blower motor switch resistor has the following features:
zThe assembly is located on the passenger side of the plenum assembly behind the glove
compartment (06010).
z Three resistance elements are mounted on the resistor board to provide four A/C blower motor
speeds.
z Depending on the heater blower motor switch position, series resistance is added or bypassed
in the A/C blower motor circuit to decrease or increase A/C blower motor speed.
z An overheating protective device (thermal limiter) will open the resistor coil circuit when the
temperature reaches 105°- 110°C (221°-230°F), interrupting the blower motor operation in all
speeds except HI.
z The thermal limiter cannot be reset and is not serviceable.
Control Actuators
Temperature Control Cable
The temperature control cable (19988) has the following features:
zThe cable assembly has a constant tension (pull- pull) dual cable design.
z The pull- pull design allows for constant smooth communication between the temperature control
knob and the air temperature blend door.
z The control cable can only be installed as an assembly.
Vacuum Control Motors
The vacuum control motors (18A318) control the position of the doors directing the air flow to the
different outlets. There are two types of vacuum control motors used in this system:
zSingle- diaphragm for air inlet and windshield defroster door operations.
z Double- diaphragm for air damper door operations.
Single- diaphragm motors have two positions:
z Shaft extended with no vacuum applied.
z Shaft retracted with vacuum applied.
Double- diaphragm motors have three positions:
z Shaft extended with no vacuum applied to either port.
z Shaft halfway retracted with vacuum applied to only one port. Klj . 3 ba
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z
Shaft fully retracted with vacuum applied to both ports. Klj . 4 ba
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DIAGNOSIS AND TESTING
Control Components
Refer to
Section 412 - 00 .
SECTION 412-
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REMOVAL AND INSTALLATION
Control Assembly
Removal
1. Remove the center instrument panel register. For additional information, refer to Section 412 -
01 .
2. Remove the screws.
3. Disconnect the connectors.
4. Using the special tool, disconnect the temperature control cable from the control head.
SECTION 412-
04: Control Components 2003 Mustang Workshop Manual Special Tool(s)
Remover, Heater Control
Cable Retainer
412-
088 (T94P-18532- A) Klj . 1 ba
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5. Remove the nuts and disconnect the vacuum connector.
Installation 1. Align the blend door driver to the full heat position.
2. Place the temperature control knob in the full WARM position.
3. Attach the cable drive to the control head. Klj . 2 ba
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4. Rotate the knob back and forth from full WARM to full COOL.
5. Check the cable control for correct range of movement.
6. Connect the electrical connectors.
7. Install the vacuum connector and nuts. Klj . 3 ba
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