heater FORD MUSTANG 2003 Manual Online

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
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

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
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

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
42003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

DESCRIPTION AND OPERATION
Instrument Cluster and Panel Illumination
The instrument cluster and panel illumination system illuminates the following components:
zinstrument cluster (10849)
z audio unit (18806)
z A/C- heater control
z fog lamp switch
z transmission range indicator
z traction control switch
z rear window defrost control switch
The instrument cluster is a hybrid electronic cluster (HEC), which uses both hardwired circuitry and the
standard corporate protocol (SCP) communication network to transmit and receive information. The
Mustang instrument cluster backlighting has illumination bulbs that are installed separately from the
instrument cluster. The Cobra instrument cluster has a laminated, electroluminescent applique to
backlight the cluster . The electroluminescent applique and instrument cluster must be installed as an
assembly. SECTION 413-
00: Instrument Cluster and Panel Illumination 2003 Mustang Workshop Manual Klj . 1 ba
12003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

REMOVAL AND INSTALLATION
Battery Cables
Removal
WARNING: Batteries normally produce explosive gases which can cause personal injury.
Therefore, do not allow flames, sparks or lighted substances to come near the battery. When
charging or working near a battery, always shield your face and protect your eyes. Always
provide ventilation. Failure to follow these instructions may result in personal injury.
WARNING: Keep out of the reach of children. Batteries contain sulfuric acid. Avoid
contact with skin, eyes, or clothing. Also, shield your eyes when working near the battery to
protect against possible splashing of the acid solution. In case of acid contact with skin or
eyes, flush immediately with water for a minimum of 15 minutes and get prompt medical
attention. If acid is swallowed, call a physician immediately. Failure to follow these instructions
may result in personal injury.
All vehicles
1. Remove the battery. For additional information, refer to Battery in this section.
2. If equipped, unplug the engine heater intermediate connection.
3. Remove the battery ground cable harness bolt from the radiator support and release the cable harness locators.
4. Disconnect the battery cable harness electrical connectors.
5. CAUTION: The square terminal from the battery must be installed first, followed by
SECTION 414-
01: Battery, Mounting and Cables 2003 Mustang Workshop Manual Klj . 1 ba
62003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

the round terminal from the generator. Reversing this sequence may cause circuit failure
or arcing.
Remove the battery junction box nut and position the positive battery cable and generator B+
cable aside.
Vehicles with 3.8L and 4.6L 2V engines 6. Remove the cable harness front support bracket by removing the nut, and position the bracket aside.
Vehicles with 4.6L 4V engines 7. Remove the nut and position the left upper battery cable bracket aside.
All vehicles 8. Raise and support the vehicle. For additional information, refer to Section 100 - 02 .
9. NOTE: 4.6L 4V shown; 3.8L and 4.6L 2V similar.
If equipped, remove the block heater plug from the block heater and the harness locators from Klj . 2 ba
62003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...