audio FORD MUSTANG 2003 User Guide

PINPOINT TEST C: CONTINUOUS SEEK/SCAN IN AM/FM
PINPOINT TEST D: NO SOUND FROM ONE OR MORE OF THE
SPEAKERS —
NOT ALL SPEAKERS z
Is the noise eliminated? jumper cable. When noise is eliminated,
PROVIDE a permanent ground where
necessary. TEST the system for normal
operation.
Test Step Result / Action to Take
C1 CHECK OPERATION OF THE
SEEK/SCAN FUNCTIONS z
Key in ON position.
z Operate the SEEK/SCAN functions
with the audio unit in both AM and FM
tuner modes.
z Do the SEEK/SCAN functions
search continuously? Yes
GO to
C2 .
No
The system is OK. C2 CHECK ANTENNA FOR DAMAGE
z
Key in OFF position.
z Disconnect: Antenna Lead Terminal.
z Measure the resistance between the
antenna cable lead terminal and the
end of the antenna grid wire.
z Is the resistance less than 8 ohms? Yes
GO to
C3 .
No
REPAIR the antenna. REFER to Section 415 - 02
C3 SUBSTITUTE ANTENNA EXTENSION
CABLE z
Substitute a known good antenna
cable between the audio unit and the
antenna.
z Key in START position.
z Check the operation of the audio unit.
z Is the noise eliminated? Yes
INSTALL a new antenna extension cable. REFER
to
Section 415 - 02 . TEST the system for normal
operation.
No
REINSTALL the original cable. REMOVE the
audio unit and SEND it to an authorized Ford
audio system repair facility. TEST the system for
normal operation. Test Step Result / Action to
Take D1 CHECK FOR SOUND
z
Key in ON position.
z Turn on the audio unit.
z Are all speakers without sound? Yes
GO to
Pinpoint Test E .
No
For convertible,
GO to D2 .
For coupe, GO to
D4 . Klj . 7 ba
242003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

For Mach 1000
subwoofer
speakers,GO to
D8
.
D2 CHECK CIRCUITS BETWEEN THE AFFECTED SPEAKER(S) AND
SUBWOOFER AMPLIFIERS z
Disconnect: Subwoofer Amplifier C4108a.
z Disconnect: Subwoofer Amplifier C4109b.
z Disconnect: Affected Speaker(s).
z Measure the resistance between the subwoofer amplifier and the
affected speaker(s) and between the subwoofer amplifier and ground
as follows:
z Are the resistances less than 5 ohms between the subwoofer
amplifier and the affected speaker(s) and greater than 10,000
ohms between the subwoofer amplifier and ground? Speaker Circuits Affected Speaker Pin Subwoofer Amplifier Pin Circuit
RF 1 (convertible only) LH 7 822 (BK/LG)
RF 2 (convertible only) LH 8 287 (BK/WH)
LF 1 (convertible only) LH 7 822 (BK/LG)
LF 2 (convertible only) LH 8 287 (BK/WH)
RR 1 RH 7 822 (BK/LG)
RR 2 RH 8 287 (BK/WH)
LR 1 RH 7 822 (BK/LG)
LR 2 RH 8 287 (BK/WH) Yes
GO to
D3 .
No
REPAIR the circuit
(s) in question.
TEST the system
for normal
operation. D3 CHECK CIRCUITS BETWEEN THE AUDIO UNIT AND THE
SUBWOOFER AMPLIFIERS z
Disconnect: Audio Unit C290b.
z Disconnect: Subwoofer Amplifier C4108a.
z Disconnect: Subwoofer Amplifier C4109b.
z Measure the resistance between the subwoofer amplifier and the
audio unit C290b and between the subwoofer amplifier and ground
as follows:
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? Speaker Circuits Audio Unit C290b Pin Subwoofer Amplifier Pin Circuit
2 LH 5 167 (BN/OG)
6 RH 5 169 (LG/BK)
1 LH 6 168 (RD/BK)
5 RH 6 172 (LB/RD) Yes
GO to
D6 .
No
REPAIR the circuit
(s) in question.
TEST the system
for normal
operation. D4 CHECK CIRCUITS BETWEEN THE AFFECTED SPEAKER(S) AND
SUBWOOFER AMPLIFIER z
Disconnect: Subwoofer Amplifier C4109b.
z Disconnect: Affected Speaker(s).
z Measure the resistance between the subwoofer amplifier and the Yes
GO to
D5 . Klj . 8 ba
242003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

affected speaker(s) and between the subwoofer amplifier and ground
as follows:
z Are the resistances less than 5 ohms between the subwoofer
amplifier and affected speaker(s) and greater than 10,000 ohms
between the subwoofer amplifier and ground? Speaker Circuits Affected Speaker Pin Subwoofer Amplifier Pin Circuit
RR 1 7 822 (BK/LG)
RR 2 8 287 (BK/WH)
LR 1 7 822 (BK/LG)
LR 2 8 287 (BK/WH) No
REPAIR the circuit
(s) in question.
TEST the system
for normal
operation.
D5 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
D6 .
No
REPAIR the circuit
(s) in question.
TEST the system
for normal
operation. D6 CHECK SPEAKER(S)
z
Key in OFF position.
z Substitute the affected speaker with a known good component.
z Key in ON position.
z Turn on the audio unit.
z Is the affected speaker(s) operational? Yes
INSTALL a new
speaker. TEST the
system for normal
operation.
No
GO to
D7 .
D7 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 affected speaker(s) operational? 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 Klj . 9 ba
242003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

for normal
operation.
D8 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 subwoofer amplifier pin 5,
circuit 828 (VT/LB) (left amplifiers) and ground, or between pin 5,
circuit 829 (WH/VT) (right amplifiers) and ground.
z Is the voltage greater than 10 volts? Yes
GO to
D9 .
No
REPAIR the circuit
(s) in question.
TEST the system
for normal
operation. D9 CHECK FOR GROUND TO THE AFFECTED SUBWOOFER
AMPLIFIER z
NOTE: Ground circuit 694 is located in the same cavity in all four
subwoofer amplifiers.
z Measure the resistance between affected subwoofer amplifier pin 2,
circuit 694 (BK/LG) and ground.
z Is the resistance less than 5 ohms? Yes
GO to
D10 .
No
REPAIR the circuit
(s) in question.
TEST the system
for normal
operation. D10 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 subwoofer amplifiers.
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). Yes
GO to
D12 .
No
GO to D11 . Klj . 10 ba
242003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

z
Does the voltage vary as the volume is adjusted? D11 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:
z Is the resistance less than 5 ohms between the audio unit and
subwoofer amplifier and greater that 10,000 ohms between the
subwoofer amplifier and ground? Speaker Circuits Audio Unit C290a Pin Subwoofer Amplifier Pin Circuit
2 8 172 (LB/RD)
8 7 169 (LG/BK) Yes
SEND the audio
unit to an
authorized Ford
audio system
repair facility.
TEST the system
for normal
operation.
No
REPAIR the circuit
(s) in question.
TEST the system
for normal
operation.
D12 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
D13 .
D13 CHECK FOR AN OPEN AND SHORT TO GROUND BETWEEN THE
AFFECTED SUBWOOFER AND ITS RESPECTIVE AMPLIFIERS z
Key in OFF position. Yes Klj . 11 ba
242003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

PINPOINT TEST E: NO SOUND FROM ALL OF THE SPEAKERS z
Disconnect: Respective Amplifier to Subwoofer Speaker Connector.
z Measure the resistance between the affected subwoofer speaker and
its respective amplifiers, and between the affected subwoofer
speaker and ground as follows:
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? 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) 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) INSTALL a new
subwoofer
amplifier.
No
REPAIR the circuit
(s) in question.
TEST the system
for normal
operation.
Test Step Result / Action to Take
E1 CHECK FOR AUDIO UNIT
OPERATION z
Key in ON position.
z Turn the audio unit on.
z Does the audio unit
display illuminate? Yes
GO to
E2 .
No
GO to Pinpoint Test A .
E2 CHECK THE SPEAKER
OPERATION z
Check the operation of all
speakers.
z Are all speakers
inoperative? Yes
REMOVE the audio unit and SEND it to an authorized Ford
audio system repair facility. TEST the system for normal
operation. Klj . 12 ba
242003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

PINPOINT TEST F: POOR QUALITY SOUND FROM ONE OR MORE
SPEAKERS (NOT ALL SPEAKERS) No
GO to
Pinpoint Test D .
Test Step Result / Action to
Take F1 CHECK SOUND QUALITY
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 Do all speakers have poor sound quality? Yes
REMOVE the
audio unit and
SEND it to an
authorized Ford
audio system
repair facility.
TEST the system
for normal
operation.
No
For convertible,
GO to
F2 .
For coupe, GO to
F4 .
For Mach 1000
subwoofer
speakers,GO to
F6 .
F2 CHECK CIRCUITS BETWEEN AFFECTED SPEAKER(S) AND
SUBWOOFER AMPLIFIERS z
Disconnect: Subwoofer Amplifier C4108a.
z Disconnect: Subwoofer Amplifier C4109b.
z Disconnect: Affected Speaker(s).
z Measure the resistance between the subwoofer amplifier and the
affected speaker(s) and between subwoofer amplifier and ground as
follows:
z Are the resistances less than 5 ohms between the subwoofer
amplifier and the affected speaker(s) and greater than 10,000 Speaker Circuits Affected Speaker Pin Subwoofer Amplifier Pin Circuit
RF 1 (convertible only) LH 7 822 (BK/LG)
RF 2 (convertible only) LH 8 287 (BK/WH)
LF 1 (convertible only) LH 7 822 (BK/LG)
LF 2 (convertible only) LH 8 287 (BK/WH)
RR 1 RH 7 822 (BK/LG)
RR 2 RH 8 287 (BK/WH)
LR 1 RH 7 822 (BK/LG)
LR 2 RH 8 287 (BK/WH) Yes
GO to
F3 .
No
REPAIR the circuit
(s) in question.
TEST the system
for normal
operation. Klj . 13 ba
242003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

ohms between the subwoofer amplifier and ground?
F3 CHECK CIRCUITS BETWEEN THE AUDIO UNIT AND THE
SUBWOOFER AMPLIFIERS z
Disconnect: Audio Unit C290b.
z Disconnect: Subwoofer Amplifier C4108b.
z Disconnect: Subwoofer Amplifier C4109b.
z Measure the resistance between subwoofer amplifier and audio unit
C290a and between subwoofer amplifier and ground as follows:
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? Speaker Circuits Audio Unit C290a Pin Subwoofer Amplifier Pin Circuit
2 LH 5 167 (BN/OG)
6 RH 5 169 (LG/BK)
1 LH 6 168 (RD/BK)
5 RH 6 172 (LB/RD) Yes
GO to
F6 .
No
REPAIR the circuit
(s) in question.
TEST the system
for normal
operation. F4 CHECK CIRCUITS BETWEEN AFFECTED SPEAKER(S) AND
SUBWOOFER AMPLIFIER z
Disconnect: Subwoofer Amplifier C4109b.
z Disconnect: Affected Speaker(s).
z Measure the resistance between subwoofer amplifier and the
affected speaker(s) and between subwoofer amplifier and ground as
follows:
z Are the resistances less than 5 ohms between the subwoofer
amplifier and the affected speaker(s) and greater than 10,000
ohms between the subwoofer amplifier and ground? Speaker Circuits Affected Speaker Pin Subwoofer Amplifier Pin Circuit
RR 1 7 822 (BK/LG)
RR 2 8 287 (BK/WH)
LR 1 7 822 (BK/LG)
LR 2 8 287 (BK/WH) Yes
GO to
F5 .
No
REPAIR the circuit
(s) in question.
TEST the system
for normal
operation. F5 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
F10 .
No
REPAIR the circuit
(s) in question.
TEST the system
for normal
operation. F6 CHECK FOR AN AUDIO SIGNAL TO THE SUBWOOFER Klj . 14 ba
242003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

AMPLIFIER HARNESS
z
Key in OFF position.
z Disconnect: Mach 1000 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
F8 .
No
GO to F7 .
F7 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:
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 Affected Subwoofer Amplifier
Pin Circuit
2 8 172
(LB/RD) 8 7 169
(LG/BK) Yes
SEND the audio
unit to an
authorized Ford
audio system
repair facility.
TEST the system
for normal
operation.
No
REPAIR the circuit
(s) in question.
TEST the system
for normal
operation.
F8 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. Yes
INSTALL a new
subwoofer speaker
No
GO to
F9 Klj . 15 ba
242003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...

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
242003 Mustang Workshop Manual
18. 11. 2011file:///C:/Ford/2000 - 2004/tsocache/SHEF_5108/S3B~us~en~ ...