Ford Mustang (1999-2004) Service Manual: Horn (Diagnosis and Testing)
Refer to Wiring Diagrams Cell 44 , Horns/Cigar Lighter for schematic and connector information.
Special Tool(s)
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73 Digital Multimeter or equivalent 105-R0051 |
Inspection and Verification
1. Verify the customer concern by operating the horn (13832).
2. Visually inspect for obvious signs of mechanical and electrical damage.
Visual Inspection Chart
Mechanical | Electrical |
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3. If fault is not visually evident, determine the symptom and proceed to Symptom Chart.
Symptom Chart
Condition | Possible Sources | Action |
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Pinpoint Tests
PINPOINT TEST A: THE HORN DOES NOT SOUND
Test Step | Result / Action to Take |
A1 CHECK POWER SUPPLY TO HORN RELAY | Yes GO to A2 . No REPAIR the circuit in question. TEST the system for normal operation. |
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A2 CHECK HORN RELAY | Yes GO to A3 . No INSTALL a new horn relay. TEST the system for normal operation. |
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A3 CHECK HORN SWITCH SIGNAL TO HORN RELAY | Yes GO to A4 . No GO to A5 . |
Horn Switch Position
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A4 CHECK WIRE BETWEEN HORN RELAY AND HORN | Yes INSTALL new horns. TEST the system for normal operation. No REPAIR the circuit. TEST the system for normal operation. |
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A5 CHECK WIRE BETWEEN HORN RELAY AND AIR BAG SLIDING CONTACT | Yes GO to A6 . No REPAIR the circuit. TEST the system for normal operation. |
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A6 CHECK AIR BAG SLIDING CONTACT | Yes GO to A7 . No INSTALL a new air bag sliding contact. REFER to Section. TEST the system for normal operation. |
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A7 CHECK THE STEERING WHEEL SWITCH HARNESS | 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. |
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PINPOINT TEST B: THE HORN SOUNDS CONTINUOUSLY
Test Step | Result / Action to Take |
B1 CHECK HORN CIRCUIT 1 (DB) | Yes REPAIR Circuit 1 (DB) for short to battery. TEST the system for normal operation. No GO to B2 . |
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B2 CHECK HORN RELAY | Yes REINSTALL the horn relay. GO to B3 . No INSTALL a new horn relay. TEST the system for normal operation. |
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B3 CHECK CIRCUIT 6 (YE/LG) | Yes GO to B4 . No RECONNECT the air bag sliding contact. GO to B5 . |
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B4 CHECK GEM INPUT | Yes REPAIR Circuit 6 (YE/LG). TEST the system for normal operation. No INSTALL a new GEM; REFER to Section. TEST the system for normal operation. |
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B5 CHECK THE AIR BAG SLIDING CONTACT | Yes INSTALL a new air bag sliding contact. REFER to Section. TEST the system for normal operation. No GO to B6 . |
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B6 CHECK STEERING WHEEL SWITCH HARNESS | 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. |
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Horn
Torque Specifications
Horn
The horn system consists of the following:
dual horns (one high-pitched, one low-pitched)
horn switch (located underneath the driver side air bag module
[043 ...
Switch - Horn
Removal
1. Remove the driver side air bag module (043B13). Refer to Section.
2. Remove the switches.
1. Disconnect the horn wire from the switches.
2. Remove the horn switch screws and ...
Other materials:
Heated Oxygen Sensor (HO2S)
Special Tool(s)
Socket, Exhaust Gas Oxygen
Sensor
303-476 (T94P-9472-A)
Material
Item
Specification
Penetrating and Lock Lubricant
or equivalent
E8AZ-19A501-
B
Removal and Installation
1. Disconnect the battery ground ...
Interior Trim and Ornamentation
General Specifications
Torque Specifications
Interior Trim
The interior trim consists of:
A-pillar lower trim panels
door trim panels
headliner (coupe)
package tray trim panel (coupe)
quarter trim panels
upper quarter trim panels (coup ...
Axle
Special Tool(s)
2-Jaw Puller
205-D072 (D97L-4221-A) or
equivalent
Adapter for 205-S127
205-105 (T76P-4020-A3)
Bearing Preload Tool
205-395 (T93P-4220-A)
Plate, Bearing/Oil Seal
205-090 (T75L-1165-B)
Gauge, ...