AC system FORD MUSTANG 2003 Workshop Manual

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
412003 Mustang Workshop Manual
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z
Is the intersection of the two lines within the upper
and lower limits? No
GO to
E10 .
E10 CHECK FOR A NORMAL TO LOW SUCTION
PRESSURE z
Refer to the data plot used to evaluate the system low
pressure performance in Step E9.
z Is the intersection of the two lines below the lower
limit? Yes
INSTALL a new A/C
evaporator core orifice due to
a partially restricted or plugged
condition. REFER to
Section 412 - 03 . TEST the system for
normal operation.
No
INSPECT the A/C condenser
core (19712) for a partially
blocked or inadequate airflow.
TEST the system for normal
operation. E11 CHECK FOR A NORMAL SUCTION 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.
z Is the intersection of the two lines within the upper
and lower limits? Yes
GO to
E12 .
No
GO to E15 .
E12 CHECK FOR A SLOW A/C CLUTCH CYCLE RATE
z
Use the recorded data from the refrigerant system tests
to plot a vertical line for ambient temperature and a
horizontal line for total A/C clutch cycle time (time ON
plus time OFF) in seconds. Yes
INSTALL a new evaporator to
compressor suction line
(19D742) due to a partially
restricted or plugged condition.
REFER to
Section 412 - 03 .
TEST the system for normal
operation.
No
GO to E13 . Klj . 28 ba
412003 Mustang Workshop Manual
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z
Is the intersection of the two lines above the upper
limit? E13 CHECK FOR A NORMAL A/C CLUTCH OFF TIME
z
Use the recorded data from the refrigerant system tests
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 within the upper
and lower limits? Yes
INSPECT the A/C evaporator
core due to a low or restricted
airflow. TEST the system for
normal operation.
No
GO to
E14 .
E14 CHECK FOR A LONG A/C CLUTCH OFF TIME
z
Refer to the data plot used to evaluate the system A/C
clutch OFF time performance in Step E13.
z Is the intersection of the two lines above the upper
limit? Yes
INSTALL a new A/C
condenser core due to a
partially restricted or plugged
condition. REFER to
Section 412 - 03 . TEST the system for
normal operation.
No
EVACUATE and RECHARGE
the system when the
intersection of the two lines is
below the lower limit. REFER
to Air Conditioning (A/C) System Recovery, Evacuation
and Charging . TEST the
system for normal operation. E15 CHECK FOR A MISSING A/C EVAPORATOR CORE
ORIFICE z
Remove the A/C evaporator core orifice tube. Refer to
Section 412 - 03 .
z Is the A/C evaporator core orifice missing? Yes
INSTALL a new A/C
evaporator core orifice.
REFER to
Section 412 - 03 .
TEST the system for normal
operation.
No Klj . 29 ba
412003 Mustang Workshop Manual
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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
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z
Is the voltage greater than 10 volts? G2 CHECK THE BLOWER MOTOR FOR VOLTAGE
z
Key in OFF position.
z Connect: Blower Motor Jumper C238.
z Disconnect: Blower Motor C2066.
z Key in ON position.
z Measure voltage between terminals of blower motor.
z Check for voltage between circuit 249 (DB/LG) and circuit
261 (OG/BK).
z Is the voltage greater than 10 volts? Yes
INSTALL a new blower
motor. REFER to
Section 412 - 02 . TEST the system
for normal operation.
No
GO to G3 .
G3 CHECK THE A/C BLOWER MOTOR JUMPER WIRE
z
Key in OFF position.
z Disconnect: Blower Motor Jumper C238.
z Key in ON position.
z Check circuit 261 (OG/BK) for an open between C2066 and
C238- 4.
z Is the resistance greater than 5 ohms? Yes
REPAIR circuit 261
(OG/BK). TEST the system
for normal operation.
No
INSTALL a new blower
motor. REFER to
Section 412 - 02 . TEST the system
for normal operation. G4 CHECK CIRCUIT 249 (DB/LG)
z
Check for voltage between C238- 6, circuit 249 (DB/LG),
harness side and ground. Yes
GO to
G5 .
No
GO to G8 . Klj . 31 ba
412003 Mustang Workshop Manual
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z
Is the voltage greater than 10 volts? G5 CHECK CIRCUIT 249 (DB/LG) FOR OPEN
z
Check the resistance on circuit 249 (DB/LG) between C238-
3 and C2066.
z Is resistance less than 10,000 ohms? Yes
REPAIR circuit 249
(DB/LG) for an open. TEST
the system for normal
operation.
No
GO to
G6 .
G6 CHECK THE BLOWER MOTOR GROUND
z
Key in OFF position.
z Measure the resistance between the jumper C238- 3, circuit
261 (OG/BK), and ground.
z Is the resistance less than 5 ohms? Yes
GO to
G7 .
No
GO to G10 .
G7 CHECK CIRCUIT 261 (OG/BK) FOR AN OPEN CIRCUIT
z
Measure the resistance between the A/C blower motor
jumper C238- 3, circuit 261 (OG/BK) and the blower motor
switch C294a- 1. Yes
REPAIR the blower motor
jumper. TEST the system
for normal operation.
No
INSTALL a new blower
motor. REFER to
Section 412 - 02 . TEST the system
for normal operation. Klj . 32 ba
412003 Mustang Workshop Manual
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z
Is the resistance more than 10,000 ohms? G8 CHECK CIRCUIT 249 (DB/LG) FOR AN OPEN CIRCUIT
z
Key in OFF position.
z Disconnect: Function Selector Switch C294c.
z Measure the resistance between C238- 3, circuit 249
(DB/LG), harness side and C294c- 4 harness side.
z Is the resistance more than 10,000 ohms? Yes
REPAIR circuit 249
(DB/LG) for an open. TEST
the system for normal
operation.
No
GO to
G9 .
G9 CHECK CIRCUIT 181 (BN/OG), FOR VOLTAGE
z
Measure the voltage between C294c- 2, circuit 181 (BN/OG),
harness side and ground.
z Is the voltage greater than 10 volts? Yes
INSTALL a new function
selector switch. REFER to
Section 412
- 04 . TEST the
system for normal
operation.
No
REPAIR circuit 181
(BN/OG) for an open. TEST
the system for normal
operation. G10 CHECK CIRCUIT 1205 (BK) FOR AN OPEN
Yes
INSTALL a new blower
motor switch. REFER to
Section 412
- 04 . TEST the
system for normal
operation.
No
REPAIR circuit 1205 (BK).
TEST the system for
normal operation. Klj . 33 ba
412003 Mustang Workshop Manual
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PINPOINT TEST H: THE BLOWER MOTOR OPERATES
CONTINUOUSLY IN HIGH SPEED z
Check the resistance between C294a- 3, circuit 1205 (B/K)
harness side and ground.
z Is the resistance less than 5 ohms? Test Step Result / Action to Take
H1 CHECK THE FUNCTION SELECTOR SWITCH
z
Key in ON position.
z Set the blower motor speed to low.
z Check for blower motor operation in each function
selector switch position.
z Does the blower motor operate on high in all of
the function selector positions? Yes
GO to
H2 .
No
If the blower motor operates in the
OFF position, GO to H4 .
H2 CHECK CIRCUIT 261 (OG/BK) FOR A SHORT TO
GROUND z
Key in OFF position.
z Disconnect: A/C Blower Motor C2066.
z Disconnect: Blower Motor Resistor C2185.
z Disconnect: Blower Motor Switch C294a.
z Measure the resistance between C2066 circuit 261
(OG/BK), and ground.
z Is the resistance greater than 10,000 ohms? Yes
GO to
H3 .
No
REPAIR circuit 261 (OG/BK) for a
short to ground. TEST the system
for normal operation. H3 CHECK THE BLOWER MOTOR SWITCH
OPERATION z
Measure the resistance of the blower motor switch.
Refer to the chart shown.
Blower Motor Switch Test Switch
Position Conductivity Between
Terminals Yes
INSTALL a new heater blower
motor switch resistor. REFER to
Section 412
- 04 . TEST the
system for normal operation.
No Klj . 34 ba
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PINPOINT TEST I: NO OPERATION IN HIGH BLOWER SETTING z
Is the resistance less than 5 ohms? Low None
Medium/low 2 and 3 only
Medium/high 2, 3 and 4 only
High 1, 2 and 4 only INSTALL a new heater blower
motor switch. REFER to
Section 412 - 04 . TEST the system for
normal operation. H4 CHECK THE FUNCTION SELECT SWITCH FOR A
SHORT TO BATTERY z
Key in OFF position.
z Disconnect: Function Selector Switch C294c.
z Key in ON position.
z Did the blower motor stop operating? Yes
INSTALL a new function selector
switch. REFER to
Section 412 -
04 . TEST the system for normal
operation.
No
REPAIR circuit 249 (DB/LG) for a
short to battery. TEST the system
for normal operation. Test Step Result / Action to Take
I1 CHECK CIRCUIT 261 (OG/BK) FOR AN OPEN CIRCUIT
z
Key in OFF position.
z Disconnect: Blower Motor Switch C294a.
z Key in ON position.
z Turn the function selector switch to the FLOOR position.
z Measure the voltage between blower motor switch C294a,
circuit 261 (OG/BK), harness side and ground.
z Is the voltage greater than 10 volts? Yes
GO to
I2 .
No
REPAIR circuit 261 (OG/BK)
for an open circuit. TEST the
system for normal operation. I2 CHECK CIRCUIT 1205 (BK) FOR AN OPEN Klj . 35 ba
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PINPOINT TEST J: NO OPERATION IN LOWER SPEEDS
Component Tests z
Measure the resistance between C294a- 3, circuit 1205
(BK), harness side and ground.
z Is the resistance less than 10,000 ohms? Yes
REPAIR circuit 1205 (BK) for
an open. TEST the system for
normal operation.
No
INSTALL a new blower motor
switch. REFER to
Section 412 - 04 . TEST the system for
normal operation. Test Step Result / Action to Take
J1 CHECK CIRCUIT 261 (OG/BK) FOR AN OPEN
z
Disconnect: Blower Motor Resistor C294a.
z Key in ON position.
z Turn the function selector switch to the FLOOR position.
z Set the blower motor switch to low.
z Measure the voltage between the blower motor resistor
C2185- 4, circuit 261 (OG/BK), jumper side and ground.
z Is the voltage greater than 10 volts? Yes
GO to
J2 .
No
REPAIR circuit 261 (OG/BK) for
an open circuit between the
blower motor and the blower
motor resistor. TEST the
system for normal operation. J2 CHECK CIRCUIT 1205 (BK) FOR AN OPEN
z
Key in OFF position.
z Measure the resistance between the blower motor
resistor C2185- 1, circuit 1205 (BK), jumper side and
ground.
z Is the resistance less than 5 ohms? Yes
INSTALL a new blower motor
resistor. REFER to
Section 412 -
03 . TEST the system for
normal operation.
No
REPAIR circuit 1205 (BK) for an
open between the blower motor
resistor and ground. TEST the
system for normal operation. Klj . 36 ba
412003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_2308/S3B~us~en~ ...