Ford 2003 Mustang Workshop Manual page 3517

Do the DRL turn off?
B2 CHECK THE PARKING BRAKE SWITCH SIGNAL CIRCUIT
Key in OFF position.
Disconnect: DRL Module C1030.
Measure the resistance between parking brake switch C306,
Circuit 22 (LB/BK), harness side and DRL module C1030 Pin
6, Circuit 22 (LB/BK), harness side.
Is the resistance less than 5 ohms?
PINPOINT TEST C: THE DAYTIME RUNNING LAMPS ARE ON WITH
THE IGNITION SWITCH OFF
C1 CHECK THE IGNITION SWITCH INPUT TO THE DRL
MODULE FOR VOLTAGE
Key in OFF position.
Disconnect: DRL Module C1030.
Measure the voltage between DRL module C1030 Pin 3,
Circuit 298 (VT/OG), harness side and ground.
Is voltage indicated?
C2 CHECK THE IGNITION SWITCH
Check the ignition switch; refer to the Wiring Diagrams
Cell 149.
Is the ignition switch OK?
Test Step
Yes
INSTALL a new DRL
module. REFER to
Module—Daytime
Running Lamps (DRL)
TEST the system for
normal operation.
No
REPAIR the circuit. TEST
the system for normal
operation.
Result / Action to Take
Yes
GO to C2 .
No
INSTALL a new DRL module.
REFER to Module—Daytime
Running Lamps (DRL)
the system for normal
operation.
Yes
REPAIR Circuit 298 (VT/OG)
for short to battery. TEST the
system for normal operation.
No
INSTALL a new ignition switch.
REFER to Section 211-05
TEST the system for normal
operation.
.
. TEST
.