2003 FORD MUSTANG test G

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
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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
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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
412003 Mustang Workshop Manual
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