climate control FORD MUSTANG 2003 User Guide

DESCRIPTION AND OPERATION
Climate Control System
WARNING: To avoid accidental deployment and possible injury, the air bag system
backup power supply must be depleted before repairing any climate control components. To
deplete the backup power supply, disconnect the battery ground cable and wait one minute.
Failure to follow these instructions may result in personal injury.
WARNING: Carbon monoxide 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.
WARNING: R- 134a is classified as a safe refrigerant, but misuse can make it dangerous.
The following precautions must be observed:
zAlways wear safety goggles when repairing an air conditioning system.
z Avoid contact with liquid refrigerant R- 134a. R-134a vaporizes at approximately - 25°C (-
13°F) under atmospheric pressure and it will freeze skin tissue.
z Never allow refrigerant R- 134a gas to escape in quantity in an occupied space. R- 134a is
non- toxic, but it will displace the oxygen needed to support life.
z Never use a torch in an atmosphere containing R- 134a gas. R-134a is non-toxic at all
normal conditions, but when it is exposed to high temperatures, such as a torch flame, it
decomposes. During decomposition it releases irritation and toxic gases (as described in
the MSDS sheet from the manufacturer). Decomposition products are hydrofluoric acid,
carbon dioxide and water.
z Do not allow any portion of the charged air conditioning system to become too hot. The
pressure in an air conditioning system rises as the temperature rises and temperatures
of approximately 85°C (185°F) can be dangerous.
z Allow the engine to cool sufficiently prior to carrying out maintenance or serious burns
and injury can occur.
CAUTION: To avoid damaging the vehicle or A/C components, the following precautions
must be observed:
zThe A/C refrigerant of all vehicles must be identified and analyzed prior to refrigerant
charging. Failure to due so can contaminate the shop bulk refrigerant and other vehicles.
z Do not add R- 12 refrigerant to an A/C system that requires the use of R- 134a refrigerant.
These two types of refrigerant must never be mixed. Doing so can damage the A/C
system.
z Charge the A/C system with the engine running only at the low- pressure side to prevent
refrigerant slugging from damaging the A/C compressor.
z Use only R- 134a refrigerant. Due to environmental concerns, when the air conditioning
system is drained, the refrigerant must be collected using refrigerant recovery/recycling
equipment. Federal law REQUIRES that R- 134a be recovered into appropriate recovery
equipment and the process be conducted by qualified technicians who have been
certified by an approved organization, such as MACS, ASI etc. Use of a recovery machine
dedicated to R- 134a is necessary to reduce the possibility of oil and refrigerant
incompatibility concerns. Refer to the instructions provided by the equipment manufacturer when removing refrigerant from or charging the air conditioning system. SECTION 412-
00: Climate Control System - General Information 2003 Mustang Workshop Manual Klj . 1 ba
112003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_2308/S3B~us~en~ ...

z
Refrigerant R- 134a must not be mixed with air for leak testing or used with air for any
other purpose above atmospheric pressure. R- 134a is combustible when mixed with high
concentrations of air and higher pressures.
z A number of manufacturers are producing alternative refrigerant products that are
designed to be used instead of R- 134a refrigerant. The use of any unauthorized
substitute refrigerant can severely damage the A/C components. If repair is required, use
only new or recycled refrigerant R- 134a.
CAUTION: To avoid contamination of the A/C system, always observe the following:
z Keep service tools and the work area clean.
z Never open or loosen a connection before discharging the system.
z When loosening a connection, if any residual pressure is evident, allow it to leak out
before opening the fitting.
z Evacuate a system that has been opened to install a new component or one that has
been discharged through leakage before charging.
z Seal an open fitting with a cap or plug immediately after disconnecting a component
from the system.
z Clean the outside of the fittings thoroughly before disconnecting a component from the
system.
z Do not remove the sealing caps from a new component until ready to install.
z Refrigerant oil will absorb moisture from the atmosphere if left uncapped. Do not open
an oil container until ready to use, and install the cap immediately after using. Store the
oil in a clean, moisture- free container.
z Install a new O- ring seal before connecting an open fitting. Coat the fitting and the O- ring
seal with refrigerant oil before connecting.
z When installing a refrigerant line, avoid sharp bends. Position the line away from the
exhaust or any sharp edges that can chafe the line.
z Do not open a refrigerant system or uncap a new component unless it is as close as
possible to room temperature. This will prevent condensation from forming inside a
component that is cooler than the surrounding air.
The manual climate control system heats or cools the vehicle depending on the function selector
switch position and the temperature selected.
zThe function selector switch position determines heating or cooling and air distribution.
z The temperature control setting determines the air temperature.
z The heater blower motor switch (18578) varies the blower motor speed.
Principles of Operation
There are four main principles involved with the basic theory of operation:
zheat transfer
z latent heat of vaporization
z relative humidity
z effects of pressure Heat Transfer Klj . 2 ba
112003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_2308/S3B~us~en~ ...

DIAGNOSIS AND TESTING
Climate Control System
Refer to Wiring Diagrams Cell
54 , Air Conditioner/Heater for schematic and connector information.
SECTION 412-
00: Climate Control System - General Information 2003 Mustang Workshop Manual Special Tool(s)
Connector, Refrigerant
Pressure Line
412-
093 (T94P-19623- E) Set, A/C Fittings
412-
DS028 (014- 00333, D93L-
19703- B) or equivalent Vacuum Pump Kit
416-
D002 (D95L-7559- A) or
equivalent Breakout Box, EEC-V Control
System
418- 049 (014-00950, T94L-50-
EEC- V) Worldwide Diagnostic System
(WDS)
418-
F224,
New Generation STAR (NGS)
Tester
418- F052, or equivalent
diagnostic tool Pressure Test Kit
014-
R1072 or equivalent 77 III Automotive Meter
105-
R0056 or equivalent Klj . 1 ba
412003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_2308/S3B~us~en~ ...

Vacuum Schematic — Manual Climate Control System R-
134a Manifold Gauge Set
176- R032A or equivalent Refrigerant Leak Detector
216-
00001 or equivalent Klj . 2 ba
412003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_2308/S3B~us~en~ ...

Function Selector Switch Vacuum Connector
V=Vacuum
NV=No Vacuum
Inspection and Verification
1. Verify the customer's concern by operating the climate control system to duplicate the condition. 16 18476 Heater core
17 18A559 Panel/floor door (full vacuum position)
18 — Floor airflow
19 18A318 Vacuum control motor—
floor/panel door 20 — Panel vent airflow
Port No. Hose Color Function
1 White Air inlet door
2 Red Panel/floor door
3 Blue Panel/floor door
4 Yellow Panel/defrost door
5 Black Vacuum source
6 — Not used
Function Selector Switch Vacuum Application Chart Switch Port Color Function Function Selector Switch Position
MAX A/C A/C Vent OFF Floor FLR/ DEF Defrost
1 White Recirc/Fresh V NV NV V NV NV NV
2 Red Floor NV NV NV V V NV NV
3 Blue Panel/floor NV NV NV V V V NV
4 Yellow Panel/defrost V V V NV NV NV NV
5 Black Vacuum source V V V V V V V Klj . 4 ba
412003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_2308/S3B~us~en~ ...

z
Does the vacuum drop? system for normal
operation.
No
REPAIR or INSTALL a
new function selector
switch. TEST the
system for normal
operation.
A13 REVIEW THE VEHICLE'S HISTORY
z
Key in OFF position.
z Review the vehicles history.
z Did the climate control system function correctly prior to
this concern? Yes
GO to
A16 .
No
GO to A14 .
A14 CHECK THE VACUUM HOSES TO DAMPER DOORS
z
Connect a vacuum pump to each hose and try to pull a vacuum.
If the vacuum pump can pull a vacuum, the hose is plugged. If
the vacuum pump pulls a partial vacuum, the hose is restricted.
z Is a hose plugged or restricted? Yes
INSTALL a new
vacuum hose. TEST
the system for normal
operation.
No
GO to
A15 .
A15 CHECK THE VACUUM HARNESS
z
Compare the vacuum hose color in each vacuum harness to the
vacuum diagram.
z Does the hose color agree with the schematics? Yes
GO to
A16 .
No
INSTALL a new
vacuum harness. TEST
the system for normal
operation. A16 CHECK A/C VACUUM CIRCUIT
z
Check the A/C vacuum circuit for pinched or kinked vacuum
hose. Yes
REPAIR or INSTALL a
new vacuum hose.
TEST the system for
normal operation.
No
GO to
A17 . Klj . 12 ba
412003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_2308/S3B~us~en~ ...

PINPOINT TEST F: NO OPERATION IN ALL TEMPERATURE
SETTINGS
PINPOINT TEST G: THE BLOWER MOTOR DOES NOT
OPERATE/DOES NOT OPERATE CORRECTLY INSTALL a new A/C
compressor due to low
performance. REFER to
Section 412
- 03 . TEST the
system for normal operation. Test Step Result / Action to Take
F1 CHECK THE TEMPERATURE CONTROL
z
Start the engine and run at idle. Allow the engine to reach
normal operating temperature.
z Place the function selector switch in the NORMAL A/C
position.
z Adjust the temperature control to full warm position, and
physically feel the discharge air temperature at the at the
center panel vents.
z Rotate the temperature control to full cold position, and
physically feel the discharge air temperature at the center
panel vents.
z Does the discharge air temperature vary? Yes
The temperature blend
door is functioning
correctly. RETURN to the
symptom chart.
No
GO to
F2 .
F2 CHECK FOR A BROKEN A/C TEMPERATURE CONTROL
CABLE z
Remove the climate control assembly to gain access to the
control cable head.
z Move the temperature control from full warm to full cold.
z Inspect the cable control head as you move the temperature
control.
z Does the alignment mark on the control head move? Yes
INSTALL a new
evaporator housing.
REFER to
Section 412 -
02 .
No
INSTALL a new
temperature control cable
assembly. REFER to
Section 412 - 04 .
Test Step Result / Action to Take
G1 CHECK FOR VOLTAGE AT C238
z
Disconnect: Blower Motor Jumper C238.
z Key in ON position.
z Turn the blower motor selector to LOW.
z Turn the function selector to FLOOR.
z Check for voltage between C238- 6, circuit 249 (DB/LG) and
C238- 3, circuit 261 (OG/BK). Yes
GO to
G2 .
No
GO to G4 . Klj . 30 ba
412003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_2308/S3B~us~en~ ...

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
22003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_2308/S3B~us~en~ ...

GENERAL PROCEDURES
Spring Lock Coupling
Disconnect
1. Remove the A/C tube lock coupling clip (19E746), if equipped.
2. Fit the special tool to the spring lock coupling.
3. Push the tool into the cage opening to release the female fitting from the A/C tube lock coupling spring (19E576).
SECTION 412-
00: Climate Control System - General Information 2003 Mustang Workshop Manual Special Tool(s)
Remover, Refrigerant Coupling
Set
412-
039 (T84L-19623- B) Klj . 1 ba
62003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_2308/S3B~us~en~ ...

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
32003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_2308/S3B~us~en~ ...