relay FORD MUSTANG 2003 Owner's Guide

Pinpoint Tests
PINPOINT TEST A: THE HORN DOES NOT SOUND module.
z Horn switch. Test Step Result / Action to
Take A1 CHECK POWER SUPPLY TO HORN RELAY
z
Disconnect: Horn Relay.
z Measure the voltage between the horn relay connector Pin 2,
Circuit 460 (YE/LB), harness side and ground; and between the
horn relay connector Pin 5, Circuit 460 (YE/LB), harness side and
ground.
z Are the voltages greater than 10 volts? Yes
GO to
A2 .
No
REPAIR the circuit in
question. TEST the
system for normal
operation. A2 CHECK HORN RELAY
z
Check the horn relay; refer to Wiring Diagrams Cell 149.
z Is the horn relay OK? Yes
GO to
A3 .
No
INSTALL a new horn
relay. TEST the
system for normal
operation. A3 CHECK HORN SWITCH SIGNAL TO HORN RELAY
z
Measure the resistance between horn relay connector Pin 1,
Circuit 6 (YE/LG), harness side and ground under the following
conditions:
Horn Switch Position Horn Switch Position Resistance
Pressed Less than 5 ohms
Released Greater than 10,000 ohms Yes
GO to
A4 .
No
GO to A5 . Klj . 2 ba
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z
Are the resistances correct? A4 CHECK WIRE BETWEEN HORN RELAY AND HORN
z
Key in OFF position.
z Disconnect: Horn C1262.
z Disconnect: Horn C1261.
z Measure the resistance between the horn relay connector Pin 3,
Circuit 1 (DB), harness side and horn C1261 or horn C1256
harness side; and between the horn relay connector Pin 3, Circuit
1 (DB), harness side and ground.
z Is the resistance less than 5 ohms between the horn relay and
the horns, and greater than 10,000 ohms between the horn
relay and ground? Yes
INSTALL new horns.
TEST the system for
normal operation.
No
REPAIR the circuit.
TEST the system for
normal operation.
A5 CHECK WIRE BETWEEN HORN RELAY AND AIR BAG SLIDING
CONTACT z
Key in OFF position.
z Deactivate the air bag system; refer to Section 501 - 20B .
z Disconnect: Air Bag Sliding Contact C218a.
z Measure the resistance between air bag sliding contact C218a Pin
2, Circuit 6 (YE/LG), harness side and horn relay connector Pin 1,
Circuit 6 (YE/LG) harness side.
z Is the resistance less than 5 ohms? Yes
GO to
A6 .
No
REPAIR the circuit.
TEST the system for
normal operation. A6 CHECK AIR BAG SLIDING CONTACT
z
Disconnect the steering wheel switch harness from the air bag
sliding contact.
z Measure the resistance between upper air bag sliding contact Yes
GO to
A7 . Klj . 3 ba
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PINPOINT TEST B: THE HORN SOUNDS CONTINUOUSLY connector Pin 3, Circuit 6 (component side), and air bag sliding
contact C218a Pin 2, Circuit 6 (component side).
z Is the resistance less than 5 ohms? No
INSTALL a new air
bag sliding contact.
REFER to
Section 501 - 20B . TEST the
system for normal
operation. A7 CHECK THE STEERING WHEEL SWITCH HARNESS
z
Inspect the steering wheel switch harness for chafing, opens or
possible short to ground.
z Is the steering wheel switch harness OK? Yes
INSTALL a new horn
switch. REFER to
Switch
— Horn . TEST
the system for normal
operation.
No
INSTALL a new
steering wheel switch
harness. TEST the
system for normal
operation. Test Step Result / Action to Take
B1 CHECK HORN CIRCUIT 1 (DB)
z
Key in OFF position.
z Disconnect: Horn Relay.
z Does the horn continue to sound? Yes
REPAIR Circuit 1 (DB) for short to battery. TEST
the system for normal operation.
No
GO to
B2 .
B2 CHECK HORN RELAY
z
Check the horn relay; refer to Wiring
Diagrams Cell 149.
z Is the horn relay OK? Yes
REINSTALL the horn relay. GO to
B3 .
No
INSTALL a new horn relay. TEST the system for
normal operation. B3 CHECK CIRCUIT 6 (YE/LG)
z
Disconnect: Air Bag Sliding Contact
C218a .
z Does the horn continue to sound? Yes
GO to
B4 .
No
RECONNECT the air bag sliding contact. GO to
B5 .
B4 CHECK GEM INPUT
z
Disconnect: GEM C201e. Yes Klj . 4 ba
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DESCRIPTION AND OPERATION
Exterior Lighting
The exterior lighting system consists of the following components:
zheadlamps (13008)
z parking lamps
z rear lamps (13404)
z high mounted stoplamp
z license lamps
z front turn lamps
z reversing lamps
z fog lamps (if equipped)
z headlamp switch (11654)
z fog lamp switch (if equipped)
z brake pedal position (BPP) switch (13480)
z multifunction switch (13K359)
z digital transmission range (DTR) sensor (A/T)
z reversing lamp switch (M/T)
z electronic flasher
z fog lamp relays (if equipped)
SECTION 417-
01: Exterior Lighting 2003 Mustang Workshop Manual Klj . 1 ba
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DIAGNOSIS AND TESTING
Fog Lamps
Refer to Wiring Diagrams Cell
86 , Fog Lamps for schematic and connector information.
Principles of Operation
The fog lamps will only illuminate when the low beam or parking lamps are illuminated. Voltage from
the parking lamp circuit is used to activate the fog lamp relay when the fog lamp switch is ON. Voltage
from the high beam headlamp circuit will activate the fog lamp interrupt relay. When the fog lamp
interrupt relay is active, the ground path is removed from the fog lamp relay, turning off the fog lamps.
Inspection and Verification 1. Verify the customer concern by operating the fog lamps.
2. Visually inspect for the following obvious signs of mechanical and electrical damage.
3. If the concern is not visually evident, determine the symptom and proceed to Symptom Chart.
Symptom Chart SECTION 417-
01: Exterior Lighting 2003 Mustang Workshop Manual Special Tool(s)
73 III Automotive Meter or
equivalent
105-
R0057
Visual Inspection Chart Mechanical Electrical
z
Damaged headlamp switch (11654)
z Damaged fog lamp switch
z Damaged multifunction switch
(13K359) z
Blown battery junction box (BJB) Fuse 27
(20A)
z Blown central junction box (CJB) Fuse 38
(20A)
z Damaged wiring harness
z Loose or corroded connections
z Damaged fog lamp relay
z Damaged fog lamp interrupt relay
z Damaged fog lamp
Symptom Chart Klj . 1 ba
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Pinpoint Tests
PINPOINT TEST O: THE FOG LAMPS ARE INOPERATIVE Condition
Possible Sources Action
z The fog lamps are
inoperative z
BJB Fuse 27 (20A).
z CJB Fuse 38 (20A).
z Circuitry.
z Fog lamp relay.
z Fog lamp interrupt
relay.
z Headlamp switch.
z Fog lamp switch.
z Multifunction switch. z
GO to Pinpoint Test O .
z The individual fog lamp is
inoperative z
Fog lamp bulb.
z Circuitry. z
GO to Pinpoint Test P .
z The fog lamps are on
continuously z
Fog lamp relay.
z Circuitry.
z Fog lamp switch. z
GO to Pinpoint Test Q .
Test Step Result / Action
to Take O1 CHECK THE PARK LAMPS
z
Place the headlamp switch in the PARK position.
z Place the multifunction switch in low beam position.
z Do the park lamps illuminate? Yes
Turn off the
headlamp switch.
GO to
O2 .
No
GO to Pinpoint Test L .
O2 CHECK THE FOG LAMP RELAYS
z
Disconnect: Fog Lamp Relay.
z Disconnect: Fog Lamp Interrupt Relay.
z Check the fog lamp relay and fog lamp interrupt relay; refer to Wiring
Diagrams Cell 149.
z Are the relays OK? Yes
GO to
O3 .
No
INSTALL new
relay(s). TEST
the system for
normal
operation. O3 CHECK THE CIRCUIT 12 (LG/BK)
z
Measure the voltage between fog lamp interrupt relay connector Pin 1,
Circuit 12 (LG/BK), harness side and ground. Yes
GO to
O4 .
No
REPAIR the
circuit. TEST the
system for
normal
operation. Klj . 2 ba
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z
Is the voltage greater than 0 volts? O4 CHECK CIRCUIT 275 (YE)
z
Measure the resistance between fog lamp interrupt relay connector Pin
4, Circuit 275 (YE), harness side and fog lamp relay connector Pin 85,
Circuit 275 (YE), harness side.
z Is the resistance less than 5 ohms? Yes
GO to
O5 .
No
REPAIR the
circuit. TEST the
system for
normal
operation. O5 CHECK CIRCUIT 477 (LB/BK) FOR OPEN
z
Measure the voltage between fog lamp relay connector Pin 30, Circuit
477 (LB/BK), harness side and ground.
z Is the voltage greater than 10 volts? Yes
GO to
O6 .
No
REPAIR the
circuit. TEST the
system for
normal
operation. O6 CHECK CIRCUIT 188 (WH/BK)
z
Disconnect: Fog Lamp Switch C240.
z Measure the resistance between fog lamp switch C240 Pin 1, Circuit
188 (WH/BK), harness side and fog lamp relay connector Pin 86,
Circuit 188 (WH/BK), harness side; and between fog lamp switch C240
Pin 1, Circuit 188 (WH/BK), harness side and ground. Yes
GO to
O7 .
No
REPAIR the
circuit. TEST the
system for
normal
operation. Klj . 3 ba
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PINPOINT TEST P: THE INDIVIDUAL FOG LAMP IS INOPERATIVE z
Is the resistance less than 5 ohms? O7 CHECK CIRCUIT 1205 (BK)
z
Measure the resistance between fog lamp interrupt relay connector Pin
2, Circuit 1205 (BK), and ground.
z Is the resistance less than 5 ohms? Yes
GO to
O8 .
No
REPAIR the
circuit. TEST the
system for
normal
operation. O8 CHECK THE FOG LAMP SWITCH
z
Measure the resistance between fog lamp switch C240 Pin 1, Circuit
188 (WH/BK), connector side and fog lamp switch C240 Pin 2, Circuit
14 (BN), connector side with the fog lamp switch on.
z Is the resistance less then 5 ohms? Yes
REPAIR Circuit
478 (TN/OG).
TEST the system
for normal
operation.
No
INSTALL a new
fog lamp switch.
TEST the system
for normal
operation.
Test Step Result / Action to
Take P1 CHECK THE GROUND TO THE FOG LAMP
z
Key in OFF position.
z Disconnect: Inoperative Fog Lamp.
z Measure the resistance between inoperative fog lamp C162 Pin
1 (RH) or C152 Pin 1 (LH), Circuit 1205 (BK), harness side and
ground. Yes
REPAIR Circuit 478
(TN/OG) for open.
TEST the system for
normal operation. Klj . 4 ba
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PINPOINT TEST Q: THE FOG LAMPS ARE ON CONTINUOUSLY z
Is the resistance less than 5 ohms? No
REPAIR Circuit 1205
(BK). TEST the system
for normal operation.
Test Step Result / Action to Take
Q1 CHECK THE FOG LAMP RELAY
z
Disconnect: Fog Lamp Relay.
z Are the fog lamps off? Yes
GO to
Q2 .
No
REPAIR Circuit 478 (TN/OG). TEST the system
for normal operation. Q2 CHECK FOG LAMP RELAY
z
Check the fog lamp relay; refer to
Wiring Diagrams Cell 149.
z Is the fog lamp relay OK? Yes
RECONNECT the fog lamp relay. GO to
Q3 .
No
INSTALL a new fog lamp relay. TEST the system
for normal operation. Q3 CHECK FOG LAMP SWITCH
z
Disconnect: Fog Lamp Switch C240.
z Are the fog lamps off? Yes
INSTALL a new fog lamp switch. TEST the
system for normal operation.
No
REPAIR Circuit 188 (WH/BK) for short. TEST the
system for normal operation. Klj . 5 ba
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as detected by the door ajar circuit. For vehicles equipped with the remote keyless entry feature, any
signal the GEM detects when a valid remote transmitter button is depressed will reset both the
demand and courtesy lamp battery saver timers. This battery saver relay then restores power to both
the demand and courtesy lamp circuits.
Base Courtesy and Extended Lighting
The base courtesy lighting feature provides interior lighting for the convenience of the vehicle's
occupants. The courtesy lamps consist of the map/dome lamps for the coupe and the map lamps for
the convertible. All lamps designated as courtesy lamps will be illuminated whenever the GEM detects
that the driver or passenger doors become ajar, by means of the driver or passenger door ajar circuits.
The courtesy lamps will also be illuminated when the GEM detects that the dome lamp switch has
been activated, by means of the dome lamp switch circuit.
The extended courtesy lighting feature provides temporary extended illumination of the courtesy lamps
after the customer has entered the vehicle. The courtesy lamps will remain illuminated for 25 seconds
after the GEM detects that the driver and passenger doors are closed, as detected by the door ajar
circuits. The extended courtesy lighting feature will be terminated after the 25 second time-
out period,
or if the GEM detects that the ignition switch has been moved from the OFF position to either the RUN,
ACC, or START positions.
Demand Lighting
The GEM does not provide any special features to the demand lighting group with the exception of
providing a power source when the battery saver feature is active. The demand lighting group consists
of the luggage compartment lamp, the driver and passenger vanity mirror lamps, and the map lamps.
Illuminated Entry with Remote Keyless Entry
The illuminated entry with remote keyless entry feature, provides power to the courtesy lamps when
the remote transmitter is used. When the GEM detects that the ignition switch is in the OFF or key out
positions, and it detects that a valid remote transmitter unlock button has been depressed, power to
the courtesy lamps will be enabled. The courtesy lamp circuit will remain powered until one of the
following occurs:
zThe GEM detects that the ignition switch has been moved from the OFF, to the RUN, START,
or ACC position.
z The GEM detects any valid remote transmitter lock button is depressed.
z The courtesy lamp circuit has been powered for 25 seconds.
If the GEM detects any valid remote transmitter unlock button has been depressed, and the ignition
switch is in the OFF or key out position during the 25 second time- out, the courtesy lamp circuits will
remain powered for an additional 25 seconds.
Inspection and Verification
1. The interior lighting system is a generic electronic module (GEM) controlled system.
2. Verify the customer concern by operating the interior lighting system.
3. Visually inspect for the following obvious signs of mechanical and electrical damage. Klj . 2 ba
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