cooling FORD MUSTANG 2003 Workshop Manual

Symptom Chart
Condition
Possible Sources Action
z Incorrect/erratic direction
of airflow from outlet(s) z
No vacuum to A/C heater
function switch selector.
z A/C heater function selector
switch leaks vacuum.
z Kinked/pinched vacuum hose.
z Leaking vacuum control
motor.
z Leaking A/C vacuum check
valve.
z Leaking A/C vacuum reservoir
tank and bracket.
z Vacuum actuator arm not
connected to door crank. z
Go To Pinpoint
Test A .
z Insufficient, erratic, or no
heat z
Low engine coolant level.
z Thermostat stuck open.
z Disengaged/damaged
temperature cable. z
Go To Pinpoint
Test B .
z The A/C does not
operate/does not operate
correctly z
CASS strategy failure.
z Open fuses.
z A/C clutch relay.
z Shorted blend door actuator.
z Powertrain control module.
z Circuitry short/open.
z A/C cycling switch damaged.
z A/C system discharged/low
charge.
z Function selector switch
damaged.
z A/C pressure cut-off switch
damaged.
z A/C compressor clutch
damaged. z
Go To Pinpoint
Test C .
z The A/C is always on zCircuitry short/open.
z A/C cycling switch.
z A/C heater function selector
switch.
z Constant control relay
module.
z Incorrect A/C clutch air gap. z
Go To Pinpoint
Test D .
z Insufficient A/C cooling zRestricted A/C evaporator
core orifice.
z Low refrigerant level. z
Go To Pinpoint
Test E .
z No operation in all the
temperature settings z
Damaged blend door actuator
cable.
z Damaged air temperature
control door. z
Go To Pinpoint
Test F .
z The blower motor does
not operate z
Open fuse.
z Circuitry open/shorted.
z Damaged heater blower
motor switch (18578).
z Damaged heater blower
motor switch resistor (18591).
z Damaged blower motor relay.
z Damaged blower motor. z
Go To Pinpoint
Test G .
z The blower motor
operates continuously in z
Circuitry short/open.
z Damaged heater blower z
Go To Pinpoint Klj . 6 ba
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PINPOINT TEST B: INSUFFICIENT, ERRATIC, OR NO HEAT z
Does the vacuum control motor hold a vacuum? A20 CHECK THE VACUUM CONTROL MOTOR INSTALLATION
z
Key in OFF position.
z Check the attachment of the vacuum control motor arm to
damper door.
z Is the vacuum control motor arm attached to the door or
door crank arm? Yes
REPAIR or INSTALL a
new damper door.
TEST the system for
normal operation.
No
CONNECT the vacuum
control motor arm to
the door and check
operation. TEST the
system for normal
operation.
Test Step Result / Action to Take
B1 CHECK FOR CORRECT ENGINE COOLANT LEVEL
z
Key in OFF position.
z Check the engine coolant level when hot and cold.
z Is the engine coolant at the correct level (hot/cold) as
indicated on the engine coolant recovery reservoir? Yes
GO to
B2 .
No
GO to B3 .
B2 CHECK FOR HOT WATER TO THE HEATER CORE INLET
HOSE WARNING: The heater core inlet hose will become
too hot to handle and may cause serious burns if the
system is working correctly.
z Key in START position.
z Allow the engine to reach normal operating temperature.
z Feel the heater core inlet hose. Yes
GO to
B4 .
No
TEST the engine cooling
system for correct
operation. REFER to
Section 303 - 03A or
Section 303 - 03B . Klj . 14 ba
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PINPOINT TEST C: THE A/C DOES NOT OPERATE/DOES NOT
OPERATE CORRECTLY z
Is the heater core inlet hose too hot to handle? B3 CHECK THE ENGINE COOLING SYSTEM INCLUDING
RADIATOR CAP FOR LEAKS z
Fill the engine cooling system to specified level.
z NOTE: It is not necessary to check the components
separately at this time.
z Pressure check the engine cooling system. Refer to Section 303 - 03A or
Section 303 - 03B .
z Does the engine cooling system, including the radiator
cap, hold pressure? Yes
GO to
B4 .
No
Pressure test the heater
core. REFER to
Component Tests, Heater
Core — Pressure Test. B4 CHECK THE HEATER CORE OUTLET HOSE FOR HOT
WATER z
Feel the heater core outlet hose.
z Is the heater core outlet hose cool or cold? Yes
TEST the heater core for a
plugged or partially
plugged condition. REFER
to
Section 303 - 03A or
Section 303 - 03B .
No
GO to Pinpoint Test E .
Test Step Result / Action to Take
C1 CHECK THE PCM PID WACF
z
Connect the diagnostic tool.
z Turn the function selector to the OFF position.
z Key in ON position.
z Enter the following diagnostic mode on the diagnostic
tool:
z Monitor the PCM PID WACF while turning the function
selector.
z Does the PCM PID WACF read YES? Yes
REFER to the Powertrain
Control/Emissions Diagnosis
(PC/ED) manual.
No
GO to
C2 .
C2 CHECK THE PCM PID WACF WITH THE A/C ON
z
Turn the function selector switch to the A/C position.
z Enter the following diagnostic mode on the diagnostic Yes
REFER to the Powertrain Klj . 15 ba
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PINPOINT TEST E: INSUFFICIENT A/C COOLING C294c-
3, circuit 348 (PK), harness side and ground.
z Is there voltage present? No
INSTALL a new function
selector switch. REFER to
Section 412
- 04 . TEST the
system for normal operation. D5 CHECK FOR A SHORTED CLUTCH INPUT
z
Key in OFF position.
z Disconnect: A/C Clutch C100.
z Key in ON position.
z Measure for voltage at the A/C clutch C100, circuit 347
(BK/YE), harness side and ground.
z Is there voltage present? Yes
INSTALL a new constant
control relay module. TEST the
system for normal operation.
No
CHECK the clutch air gap.
REFER to
Air Conditioning (A/C) Clutch Air Gap
Adjustment .
Test Step Result / Action to Take
E1 CHECK THE CENTER A/C REGISTER DISCHARGE
TEMPERATURE z
Carry out the refrigerant system tests. Refer to
Refrigerant System Tests in this section.
z Use the recorded data from the refrigerant system tests
to plot a vertical line for ambient temperature and a
horizontal line for center A/C register discharge
temperature.
z Is the intersection of the two lines within the upper
and lower limits? Yes
The tests indicate that the
system is functioning normally.
No
GO to
E2 . Klj . 25 ba
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to plot a vertical line for ambient temperature and a
horizontal line for A/C clutch OFF time in seconds.
z Is the intersection of the two lines above the upper
limit? DISCHARGE and RECOVER
the system to remove
excessive moisture or
refrigerant oil. REFER to
Air Conditioning (A/C) System
Recovery, Evacuation and
Charging . TEST the system
for normal operation.
No
GO to E7 .
E6 CHECK FOR A HIGH SUCTION PRESSURE
z
Refer to the data plot used to evaluate the system low
pressure performance in Step E3.
z Is the intersection of the two lines above the upper
limit? Yes
REMOVE the A/C evaporator
core orifice to repair missing or
damaged (leaking) O-
ring
seals. REFER to Section 412 -
03 . TEST the system for
normal operation.
No
INSTALL a new A/C cycling
switch when the intersection of
the two lines is below the
lower limit. REFER to Section 412 - 03 . TEST the system for
normal operation. E7 CHECK THE AMBIENT TEMPERATURE
z
Refer to the data plot used to evaluate the system A/C
clutch OFF time in Step E5.
z Is the ambient temperature above 26°C (80°F)? Yes
This is normal operation for
the refrigerant system in high
humidity conditions.
No
DISCHARGE and RECOVER
the system to correct an
overcharge condition. REFER
to
Air Conditioning (A/C) System Recovery, Evacuation
and Charging . TEST the
system for normal operation. E8 CHECK FOR A HIGH DISCHARGE PRESSURE
z
Refer to the data plot used to evaluate the system high
pressure performance in Step E2.
z Is the intersection of the two lines above the upper
limit? Yes
GO to
E9 .
No
GO to E11 .
E9 CHECK FOR A NORMAL LOW PRESSURE
z
Use the recorded data from the refrigerant system tests
to plot a vertical line for ambient temperature and a
horizontal line for compressor suction (low) pressure. Yes
REFER to
Section 303 - 03A or
Section 303 - 03B . to diagnose
the engine cooling system.
TEST the system for normal
operation. Klj . 27 ba
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Heater Core
WARNING: Carbon monoxide gas is colorless, odorless and dangerous. If it is necessary
to operate the engine with the vehicle in a closed area such as a garage, always use an exhaust
collector to vent the exhaust gases outside the closed area. Failure to follow these instructions
may result in personal injury.
1. NOTE: Testing of returned heater cores reveals that a large percentage of heater cores are
good and did not require installation of a new heater core. If a heater core leak is suspected, the
heater core must be tested by following the Plugged Heater Core Component Test before the
Heater Core Pressure Test. Carry out a system inspection by checking the heater system
thoroughly as follows:
Inspect for evidence of coolant leakage at the heater water hose to heater core attachments. A
coolant leak in the heater water hose could follow the heater core tube to the heater core and
appear as a leak in the heater core.
CAUTION: Spring- type clamps are installed as original equipment. Installation and
overtightening of non- specification clamps can cause leakage at the heater water hose
connection and damage the heater core.
2. Check the integrity of the heater water hose clamps.
Heater Core— Plugged
WARNING: The heater core inlet hose will become too hot to handle if the system is
working correctly.
1. Check to see that the engine coolant is at the correct level.
2. Start the engine and turn on the heater.
3. When the engine coolant reaches operating temperature, feel the heater core outlet hose to see if it is hot.
If it is not hot:
zthe heater core may have an air pocket.
z the heater core may be plugged.
z the thermostat is not working correctly.
Heater Core— Pressure Test
Use the radiator/heater core pressure tester to carry out the pressure test. 1. NOTE: Due to space limitations, a bench test may be necessary for pressure testing.
Drain the coolant from the cooling system. For additional information, refer to Section 303 - 03A
or
Section 303 - 03B .
2. Disconnect the heater water hoses from the heater core. For additional information, refer to Klj . 37 ba
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GENERAL PROCEDURES
Air Conditioning (A/C) System Check —
Retail Procedure
NOTE: This Retail Procedure is not eligible for claiming on Ford paid repairs (warranty and ESP).
NOTE: The engine should be run at idle for 10 minutes with the air conditioning on and set to MAX A/C
before carrying out this retail procedure.
NOTE: Read and follow all of the Warnings, Cautions and Notes at the beginning of this section before
continuing.
1. Visual inspection
Open the hood and visually inspect the heating and air conditioning systems for the following:
zCoolant reservoir for correct coolant level
z Heater hoses for deterioration or loose connections
z Radiator and condenser for debris or damaged fins restricting airflow, loose mounting or
connections
z Accessory drive belt(s) and cooling fan(s) for wear or physical damage
z Refrigerant lines and connections for physical damage or loose connections
z Compressor for physical damage or loose connections
z Suction accumulator/drier for physical damage or loose connections
z Wiring and connectors for excessive wear, loose or damaged connections, or incorrect
routing
2. A/C refrigerant analysis
zCarry out air conditioning refrigerant analysis. For additional information, refer to
Refrigerant Identification Testing in this section.
z If the refrigerant fails the analysis, discontinue diagnosis and make recommendations for
repairs.
z If the refrigerant passes the analysis, carry out the air conditioning system check.
3. Air conditioning system check
zConnect manifold gauge set or charging station with gauges to refrigerant system.
z With the vehicle in park, parking brake set, thermometer installed in center panel vent,
and air conditioning system on and set to MAX A/C, start the engine.
z Record air refrigerant system pressures while running the engine at 1,500 rpm and allow
engine to return to idle.
z Operate the blower motor in all control positions and check for correct blower speed
changes.
z With the blower motor on HI, operate air discharge mode selector in all positions and
check for correct airflow in each position.
z Operate the temperature blend selector in all positions and check for correct change in
discharge temperature. Check the air discharge temperature with the selector in the
coolest position and the air conditioning on and set to MAX A/C to determine if the air
discharge temperature is acceptable for the current ambient air temperature.
z Carry out the EATC self- test (if applicable).
If the refrigerant system pressures were low, carry out the refrigerant system leak test.
SECTION 412-
00: Climate Control System - General Information 2003 Mustang Workshop Manual Klj . 1 ba
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GENERAL PROCEDURES
Heater Hose Coupling
Disconnect
CAUTION: Do not attempt to install a new bushing, spacer or O- rings in the heater hose
coupling; damage to the heater hose coupling can result. If the heater hose coupling is the
cause of a coolant leak, the affected heater hose must be replaced as an assembly.
1. WARNING: The engine must be off, fully cool and the cooling system fully
depressurized before attempting to disconnect any heater water hoses. Failure to comply
with this warning can result in serious injury or burns from hot liquid escaping out of the
engine cooling system.
Depressurize the engine cooling system.
2. Push the heater hose toward the tube to fully expose the locking tabs.
3. NOTE: When compressing the white coupling retainer with the special tool, the special tool
must be perpendicular to and on the highest point of the coupling.
NOTE: If the heater hose coupling is accessible, the retainer tabs can be compressed by hand
to disconnect the heater hose.
Push the special tool over the coupling retainer windows to compress the retainer locking tabs.
SECTION 412-
00: Climate Control System - General Information 2003 Mustang Workshop Manual Special Tool(s)
Remover, Heater Hose Inlet
Tube
412-
042 (T85T-18539- AH) Disconnect Tool, Heater Hose
412-
127
Material Item Specification
MERPOL®
—
ESE-
M99B144- B Klj . 1 ba
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GENERAL PROCEDURES
Refrigerant System Tests
1. Connect the R- 134a Manifold Gauge Set. For additional information, refer to Manifold Gauge Set Connection in this section.
2. Adjust the climate controls for maximum cooling. zStart the engine.
z Select MAX A/C operation.
z Set the blower motor speed to maximum.
3. Stabilize the in- vehicle temperature at 21- 27°C (70-80°F).
4. NOTE: When the ambient temperatures exceed 38°C (100°F), do not run the engine above
normal idle speed.
Maintain the engine speed at 1,500 rpm.
5. Determine the compressor discharge (high) pressure. 1. Record the ambient temperature.
2. Record the discharge (high) pressure.
3.NOTE: In ambient temperatures between 38- 43°C (100-110°F), the system performance
pressures will be the same as those for ambient temperatures shown on the chart in the
32- 38°C (90- 100°F) range.
The system performance is acceptable when the pressure reading falls between the
upper and lower limits shown.
SECTION 412-
00: Climate Control System - General Information 2003 Mustang Workshop Manual Special Tool(s)
R-
134a Manifold Gauge Set
176- R032A or equivalent Klj . 1 ba
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DESCRIPTION AND OPERATION
Heating and Defrosting
The heating and defrosting system has the following features:
zControls the temperature and, during A/C operation, reduces the relative humidity of the air
inside the vehicle.
z Delivers heated or cooled air to maintain the vehicle interior temperature and comfort level.
z Controls the A/C blower motor speed.
z Cooling or heating can be adjusted to maintain the desired temperature.
z System uses a reheat method to provide conditioned air to the passenger compartment.
z The blower motor (19805) draws outside air through the air inlet duct from just below the
windshield during all system operations except for MAX A/C cooling (when recirculated air is
used).
z All airflow from the blower motor passes through the A/C evaporator core (19860).
z The temperature is then regulated by reheating a portion of the air and blending it with the
remaining cool air to the desired temperature.
z The temperature blending is varied by the air temperature control door, which regulates the
amount of air that flows through and around the heater core (18476), where it is then mixed and
distributed.
Heater Core
The heater core (18476) consists of fins and tubes arranged to extract heat from the engine coolant
and transfer it to air passing through the heater core. Blower Motor SECTION 412-
02: Heating and Ventilation 2003 Mustang Workshop Manual Klj . 1 ba
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