Ford 2003 Mustang Workshop Manual page 3450

PINPOINT TEST E: ONE HIGH BEAM HEADLAMP IS INOPERATIVE
E1 CHECK THE VOLTAGE TO THE INOPERATIVE HEADLAMP
BULB
Key in OFF position.
Disconnect: Inoperative Headlamp.
Place the headlamp switch in the ON position.
Place the multifunction switch in the high beam position.
Measure the voltage between LH headlamp C1021 Pin 2,
Circuit 12 (LG/BK), or RH headlamp C1041 Pin 2, Circuit 12
(LG/BK), harness side and ground.
Is the voltage greater than 10 volts?
PINPOINT TEST F: THE HEADLAMPS ARE ON CONTINUOUSLY
F1 CHECK THE HEADLAMP SWITCH
Key in OFF position.
Disconnect: Headlamp Switch C205.
Are the headlamps on?
F2 CHECK THE MULTIFUNCTION SWITCH
Disconnect: Multifunction Switch C202a.
Are the headlamps on?
F3 CHECK CIRCUIT 15 (RD/YE) FOR SHORT TO POWER
Measure the voltage between multifunction switch
C202a Pin 15, Circuit 15 (RD/YE), harness side and
ground.
Test Step
Test Step
Result / Action to Take
Yes
INSTALL a new headlamp
bulb; REFER to Bulb—
Headlamp in this section.
TEST the system for
normal operation.
No
REPAIR the circuit. TEST
the system for normal
operation.
Result / Action to Take
Yes
GO to F2 .
No
INSTALL a new headlamp
switch; REFER to Lamp
Switch—Headlamp in this
section. TEST the system for
normal operation.
Yes
GO to F4 .
No
GO to F3 .
Yes
REPAIR the circuit. TEST the
system for normal operation.
No
INSTALL a new multifunction
switch; REFER to Section 211-
05 . TEST the system for
normal operation.