Ford 2003 Mustang Workshop Manual page 3413

4
Speaker Circuits—Left Side
Affected Subwoofer
Speaker Pin
1
3
2
4
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?
H16 CHECK THE AUDIO UNIT
Substitute a known good audio unit.
Verify the operation of the audio unit.
Does the audio unit operate correctly?
PINPOINT TEST I: LOUD POPPING WHEN CYCLING THE IGNITION
SWITCH—CONVERTIBLE
Test Step
I1 CHECK SUBWOOFERS FOR LOUD
POPS
Key in ON position.
Listen to see whether the loud pops
are from the LH or RH subwoofer
amplifiers for the convertible.
Are the pops from both subwoofer
3
Respective Amplifier
Pin
4
3
4
3
Result / Action to Take
Yes
REMOVE the audio unit and SEND it to an
authorized Ford audio system repair facility.
TEST the system for normal operation.
187
(DB/OR)
Circuit
176
(PK/LG)
179
(OR/RD)
189
(TN/LB)
187
(DB/OR)
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.