Ford 2003 Mustang Workshop Manual page 3410

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.
Are the resistances less than 5 ohms?
H8 CHECK THE SUBWOOFER ENABLE CIRCUIT FOR POWER
Key in OFF position.
Disconnect: Subwoofer Amplifier C4109b.
Key in ON position.
With the audio unit turned on, measure the voltage between the
subwoofer amplifier C4109b pin 2, circuit 173 (DG/VT), harness side
and ground.
Is voltage indicated?
H9 CHECK CIRCUITS BETWEEN THE AUDIO UNIT AND THE
SUBWOOFER AMPLIFIER
Disconnect: Audio Unit C290b.
Disconnect: Subwoofer Amplifier C4109b.
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.
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?
H10 CHECK FOR POWER TO THE AFFECTED SUBWOOFER
AMPLIFIER
Key in OFF position.
Disconnect: Mach 1000 Affected Subwoofer Amplifier.
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.
No
REPAIR the circuit
(s) in question.
TEST the system
for normal
operation.
Yes
GO to H9 .
No
REPAIR the circuit
(s) in question.
TEST the system
for normal
operation.
Yes
GO to H10 .
No
REPAIR the circuit
(s) in question.
TEST the system
for normal
operation.
Yes
GO to H11 .
No
REPAIR the circuit
(s) in question.
TEST the system
for normal