2003 FORD MUSTANG Test G

PINPOINT TEST G: POOR QUALITY SOUND FROM ALL SPEAKERS
PINPOINT TEST H: THE SUBWOOFER IS INOPERATIVE z
Turn on the audio unit.
z Is the sound quality OK? system for normal
operation.
No
GO to
F7 .
F11 CHECK THE AUDIO UNIT
z
Key in OFF position.
z Substitute the affected audio unit with a known good component.
z Key in ON position.
z Turn on the audio unit.
z Is the sound quality OK? Yes
SEND the audio
unit to an
authorized Ford
audio system
repair facility.
TEST the system
for normal
operation.
No
REMOVE the
subwoofer
amplifier and
SEND it to an
authorized Ford
audio system
repair facility.
TEST the system
for normal
operation.
Test Step Result / Action to Take
G1 CHECK POOR SOUND QUALITY IN
ALL SPEAKERS z
Key in ON position.
z Turn on the audio unit.
z Carry out the speaker walk- around test
by pressing preset buttons 3 and 6
simultaneously.
z Is there poor quality or distortion in
all speakers? Yes
REMOVE the audio unit and SEND it to an
authorized Ford audio system repair facility.
TEST the system for normal operation.
No
GO to
Pinpoint Test F .
Test Step Result / Action to
Take H1 CHECK THE SUBWOOFER OPERATION
z
Key in ON position.
z Turn on the audio unit and listen for correct subwoofer operation.
z Are all subwoofers inoperative? Yes
GO to
H16 .
No
For convertible,
GO to H2 .
For coupe, GO to
H6 . Klj . 17 ba
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For Mach 1000
subwoofer
speakers,GO to
H10
.
H2 CHECK POWER TO THE SUBWOOFER AMPLIFIERS
z
Key in OFF position.
z Disconnect: LH Subwoofer Amplifier C4108a.
z Disconnect: RH Subwoofer Amplifier C4109b.
z Key in ON position.
z Turn on the audio unit.
z Measure the voltage between the subwoofer amplifiers pin 4, circuit
828 (VT/LB), harness side and ground; and between the subwoofer
amplifiers pin 5, circuit 828 (VT/LB), harness side and ground; and
between the subwoofer amplifiers pin 6, circuit 828 (VT/LB), harness
side and ground.
z Are the voltages greater than 10 volts? Yes
GO to
H3 .
No
REPAIR the circuit
(s) in question.
TEST the system
for normal
operation. H3 CHECK GROUND TO THE SUBWOOFER AMPLIFIERS
z
Measure the resistance between the subwoofer amplifiers C4108a
(LH) or C4109a (RH) pin 1, circuit 694 (BK/LG), harness side and
ground; and between the subwoofer amplifiers C4108a (LH) or
C4109a (RH) pin 2, circuit 694 (BK/LG), harness side and ground;
and between the subwoofer amplifiers C4108a (LH) or C4109a (RH)
pin 3, circuit 694 (BK/LG), harness side and ground.
z Are the resistances less than 5 ohms? Yes
GO to
H4 .
No
REPAIR the circuit
(s) in question.
TEST the system
for normal
operation. H4 CHECK THE SUBWOOFER AMPLIFIER ENABLE CIRCUIT FOR
POWER z
Key in OFF position.
z Disconnect: Subwoofer Amplifier C4109b.
z Disconnect: Subwoofer Amplifier C4108b.
z Key in ON position.
z Turn the audio unit on.
z Measure the voltage between the LH subwoofer amplifier C4108b pin
2, circuit 173 (DG/VT), harness side and ground; and between the
RH subwoofer amplifier C4109b pin 2, circuit 174 (GY/BK), harness
side and ground. Yes
GO to
H5 .
No
REPAIR the circuit
(s) in question.
TEST the system
for normal
operation. Klj . 18 ba
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z
Is voltage indicated? H5 CHECK THE AUDIO UNIT
z
Substitute a known good audio unit.
z Verify the operation of the audio unit.
z Does the audio unit operate correctly? Yes
SEND the audio
unit to an
authorized Ford
audio system
repair facility.
TEST the system
for normal
operation.
No
REMOVE the
subwoofer
amplifier and
SEND it to an
authorized Ford
audio system
repair facility.
TEST the system
for normal
operation.
H6 CHECK THE VOLTAGE TO THE SUBWOOFER AMPLIFIER
z
Key in OFF position.
z Disconnect: Subwoofer Amplifier C4109b.
z Key in ON position.
z Turn on the audio unit.
z Measure the voltage between the subwoofer amplifier C4109b pin 5,
circuit 828 (VT/LB), harness side and ground; between the
subwoofer amplifier C4109b pin 6, circuit 828 (VT/LB), harness side
and ground; and between the subwoofer amplifier C4109b pin 7,
circuit 828 (VT/LB), harness side and ground.
z Are the voltages greater than 10 volts? Yes
GO to
H7 .
No
REPAIR the circuit
(s) in question.
TEST the system
for normal
operation. H7 CHECK THE GROUND TO THE SUBWOOFER AMPLIFIER
z
Measure the resistance between the subwoofer amplifier C4109b pin
1, circuit 694 (BK/LG), harness side and ground; between the Yes
GO to
H8 . Klj . 19 ba
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subwoofer amplifier C4109b pin 2, circuit 694 (BK/LG), harness side
and ground; and between the subwoofer amplifier C4109b pin 3,
circuit 694 (BK/LG), harness side and ground.
z Are the resistances less than 5 ohms? No
REPAIR the circuit
(s) in question.
TEST the system
for normal
operation.
H8 CHECK THE SUBWOOFER ENABLE CIRCUIT FOR POWER
z
Key in OFF position.
z Disconnect: Subwoofer Amplifier C4109b.
z Key in ON position.
z With the audio unit turned on, measure the voltage between the
subwoofer amplifier C4109b pin 2, circuit 173 (DG/VT), harness side
and ground.
z Is voltage indicated? Yes
GO to
H9 .
No
REPAIR the circuit
(s) in question.
TEST the system
for normal
operation. H9 CHECK CIRCUITS BETWEEN THE AUDIO UNIT AND THE
SUBWOOFER AMPLIFIER z
Disconnect: Audio Unit C290b.
z Disconnect: Subwoofer Amplifier C4109b.
z Measure the resistance between the subwoofer amplifier C4109b pin
5, circuit 169 (LG/BK), harness side and the audio unit C290a pin 6,
circuit 169 (LG/BK), harness side and between the subwoofer
amplifier C4109b pin 5, circuit 169 (LG/BK), harness side and
ground; and between the subwoofer amplifier C4109b pin 6, circuit
172 (LB/RD), harness side and the audio unit C290a pin 5, circuit
172 (LB/RD), harness side and between the subwoofer amplifier
C4109b pin 6, circuit 172 (LB/RD), harness side and ground.
z Are the resistances less than 5 ohms between the subwoofer
amplifier and the audio unit and greater than 10,000 ohms
between the subwoofer amplifier and ground? Yes
GO to
H10 .
No
REPAIR the circuit
(s) in question.
TEST the system
for normal
operation. H10 CHECK FOR POWER TO THE AFFECTED SUBWOOFER
AMPLIFIER z
Key in OFF position.
z Disconnect: Mach 1000 Affected Subwoofer Amplifier.
z Measure the voltage between affected amplifier harness pins 1 and
2, circuit 828 (VT/LB) (left amplifiers) and ground, and between pins
4 and 5, circuit 829 (WH/VT) (right amplifiers) and ground. Yes
GO to
H11 .
No
REPAIR the circuit
(s) in question.
TEST the system
for normal Klj . 20 ba
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z
Is the voltage greater than 10 volts? operation.
H11 CHECK FOR GROUND TO THE SUBWOOFER AMPLIFIER
HARNESS z
NOTE: Ground circuit 694 is located in the same cavity in all four
subwoofer amplifiers.
z Measure the resistance between subwoofer amplifier pins 2, circuit
694 (BK/LG) and ground.
z Is the resistance less than 5 ohms? Yes
GO to
H12 .
No
REPAIR the circuit
(s) in question.
TEST the system
for normal
operation. H12 CHECK FOR AN AUDIO SIGNAL TO THE AFFECTED
SUBWOOFER AMPLIFIER z
Key in ON position.
z NOTE: Audio signal circuits 169 and 172 are located in the same
cavity on all four subwoofers.
z Turn on the audio unit and check for a fluctuating AC voltage
between affected subwoofer amplifier pin 8, circuit 172 (LB/RD) and
pin 7, circuit 169 (LG/BK).
z Does the voltage vary as the volume is adjusted? Yes
GO to
H14 .
No
GO to H13 .
H13 CHECK AUDIO SIGNAL CIRCUITS AT THE AFFECTED
SUBWOOFER AMPLIFIER FOR OPEN AND SHORT TO GROUND z
Key in OFF position.
z Disconnect: Audio Unit C290a.
z Measure the resistance between the affected subwoofer amplifier
and the audio unit C290a, and between the affected subwoofer
amplifier and ground as follows: Yes
SEND the audio
unit to an
authorized Ford
audio system Klj . 21 ba
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z
Is the resistance less than 5 ohms between the audio unit and
subwoofer amplifier harness and greater that 10,000 ohms
between the subwoofer amplifier harness and ground? Speaker Circuits Audio Unit C290a
Pin Subwoofer Amplifier Harness
Pin Circuit
2 8 172
(LB/RD) 8 7 169
(LG/BK) repair facility.
TEST the system
for normal
operation.
No
REPAIR the circuit
(s) in question.
TEST the system
for normal
operation.
H14 CHECK FOR AN AUDIO SIGNAL AT THE AFFECTED
SUBWOOFER z
Key in OFF position.
z Connect: Affected Subwoofer Amplifier.
z Disconnect: Affected Subwoofer Speaker.
z Key in ON position.
z Turn on the audio unit and check for a fluctuating AC voltage
between affected subwoofer as follows: For right subwoofer pin 4,
circuit 187 (DB/OG) and pin 2, circuit 189 (LG/BK) harness side; and
between pin 3, circuit 179 (OR/RD) and pin 1, circuit 176 (PK/LG)
harness side. For left subwoofer pin 1, circuit 187 (DB/OR) and pin 3,
circuit 189 (LG/BK) harness side; and between pin 2, circuit 179
(OR/RD) and pin 4, circuit 176 (PK/LG) harness side.
z Does the voltage vary as the volume is adjusted? Yes
INSTALL a new
subwoofer
speaker.
No
GO to
H15 .
H15 CHECK FOR AN OPEN AND SHORT TO GROUND BETWEEN THE
AFFECTED SUBWOOFER AND ITS RESPECTIVE AMPLIFIERS z
Key in OFF position.
z Disconnect: Affected Subwoofer.
z Disconnect: Respective Amplifier.
z Measure the resistance between the affected subwoofer speaker and
its respective amplifiers, and between the affected subwoofer
speaker and ground as follows:
Speaker Circuits— Right Side Affected Subwoofer
Speaker Pin Respective Amplifier
Pin Circuit
1 4 176
(PK/LG) 3 3 179
(OR/RD) 2 4 189
(TN/LB) Yes
INSTALL a new
subwoofer
amplifier.
No
REPAIR the circuit
(s) in question.
TEST the system
for normal
operation. Klj . 22 ba
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PINPOINT TEST I: LOUD POPPING WHEN CYCLING THE IGNITION
SWITCH—
CONVERTIBLE z
Is the resistance less than 5 ohms between the amplifier and
subwoofer speaker and greater that 10,000 ohms between the
subwoofer speaker harness and ground? 4 3 187
(DB/OR)
Speaker Circuits— Left Side Affected Subwoofer
Speaker Pin Respective Amplifier
Pin Circuit
1 4 176
(PK/LG) 3 3 179
(OR/RD) 2 4 189
(TN/LB) 4 3 187
(DB/OR) H16 CHECK THE AUDIO UNIT
z
Substitute a known good audio unit.
z Verify the operation of the audio unit.
z Does the audio unit operate correctly? Yes
SEND the audio
unit to an
authorized Ford
audio system
repair facility.
TEST the system
for normal
operation.
No
REMOVE the
subwoofer
amplifier and
SEND it to an
authorized Ford
audio system
repair facility.
TEST the system
for normal
operation.
Test Step Result / Action to Take
I1 CHECK SUBWOOFERS FOR LOUD
POPS z
Key in ON position.
z Listen to see whether the loud pops
are from the LH or RH subwoofer
amplifiers for the convertible.
z Are the pops from both subwoofer Yes
REMOVE the audio unit and SEND it to an
authorized Ford audio system repair facility.
TEST the system for normal operation. Klj . 23 ba
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amplifiers for the convertible? No
If the loud pops are from the convertible LH
subwoofer amplifier only, REPAIR circuit 173
(DG/VT). TEST the system for normal operation.
If the loud pops are from the convertible RH
subwoofer amplifier only, REPAIR circuit 174
(GY/BK). TEST the system for normal operation. Klj . 24 ba
242003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...