2003 FORD MUSTANG vacuum

REMOVAL AND INSTALLATION
Evaporator Core Housing
Removal
NOTE:
The evaporator core is not separately serviceable, it is serviced only with the evaporator core
housing assembly.
1. Disconnect the battery ground cable.
2. Recover the refrigerant. For additional information, refer to Section 412 - 00 .
3. Drain the cooling system. For additional information, refer to Section 303 - 03A or
Section 303 -
03B .
4. Remove the instrument panel. For additional information, refer to Section 501 - 12 .
5. Disconnect the heater hose couplings from the heater core. For additional information, refer to Section 412 - 00 .
6. Disconnect the vacuum connector. SECTION 412-
02: Heating and Ventilation 2003 Mustang Workshop Manual Material
Item Specification
PAG Compressor Oil (R-134a
Systems)
F7AZ- 19589- DA (Motorcraft
YN- 12-C) WSH-
M1C231-
B MERPOL®
NA ESE-
M99B144-
B Klj . 1 ba
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DISASSEMBLY AND ASSEMBLY
Evaporator Core Housing
Disassembly
1. Remove the evaporator core housing. For additional information, refer to Evaporator Core Housing in this section.
2. Remove the foam weather seal.
3. Remove the screws and remove the heater core.
4. Remove the screws and remove the A/C recirculating air duct.
5. Remove the vacuum reservoir. 1. Disconnect the vacuum line.
2. Remove the screw.
SECTION 412-
02: Heating and Ventilation 2003 Mustang Workshop Manual Klj . 1 ba
42003 Mustang Workshop Manual
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6. Remove the heater air damper door motor.
1. Disconnect the vacuum lines.
2. Loosen the nuts and unclip the motor.
7. Release the vacuum harness from the housing.
8. Remove the screws and remove the resistor.
9. Disconnect the jumper wire. Klj . 2 ba
42003 Mustang Workshop Manual
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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
42003 Mustang Workshop Manual
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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
42003 Mustang Workshop Manual
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z
Shaft fully retracted with vacuum applied to both ports. Klj . 4 ba
42003 Mustang Workshop Manual
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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
42003 Mustang Workshop Manual
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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
42003 Mustang Workshop Manual
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