Ford 2003 Mustang Workshop Manual page 3254

The climate control
illumination is inoperative
The audio system
illumination is inoperative
A single illumination source
is inoperative
Pinpoint Tests
PINPOINT TEST A: THE CONTROL ILLUMINATION IS INOPERATIVE
Test Step
A1 CHECK PARKING LAMPS
Place the headlamp switch in the ON
position.
Are the exterior lamps on?
A2 CHECK HEADLAMP SWITCH
Key in OFF position.
Carry out the headlamp switch
components test;
Refer to Wiring Diagrams Cell
schematic and connector information.
.
Is the headlamp switch OK?
A3 CHECK CIRCUIT 1045 (DB/WH)
Place the headlamp switch in the ON
position.
Rotate the instrument panel dimmer
switch to the full illumination position.
Measure voltage between central
junction box (CJB) fuse 37 (5A) and
ground.
Is the voltage greater than 10 volts?
PINPOINT TEST B: THE INSTRUMENT CLUSTER ILLUMINATION IS
INOPERATIVE
B1 CHECK VOLTAGE TO INSTRUMENT CLUSTER
ILLUMINATION
Disconnect: Instrument Cluster .
Place the headlamp switch in the ON position.
Rotate the instrument panel dimmer switch to the full
Bulb(s).
Circuitry.
Bulb(s).
Circuitry.
Audio unit.
Circuitry.
Switch.
Yes
Place the headlamp switch in the OFF position.
GO to
No
REFER to
Yes
RECONNECT the headlamp switch. GO to
No
INSTALL a new headlamp switch. REFER to
149 for
Section 417-01
operation.
Yes
REPAIR circuit 19 (LB/RD). TEST the system for
normal operation.
No
REPAIR circuit 1045 (DB/WH). TEST the system
for normal operation.
Test Step
Go To Pinpoint
Test C
Go To Pinpoint
Test D
Go To Pinpoint
Test E
Result / Action to Take
A2 .
Section 417-01 .
. TEST the system for normal
Result / Action to Take
Yes
GO to B2
.
.
.
A3 .
.