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)
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:
Electronic Engine Controls (Description and Operation)
The electronic engine controls consist of the following:
powertrain control module (PCM)
throttle position (TP) sensor
idle air control (IAC) valve
engine coolant temperature (ECT) sensor
cylinder head temperature sensor
camshaft position ...
Transmission Fluid Cooler Tubes
Removal
1. Disconnect the battery cables.
2. Raise and support the vehicle. For additional information, refer to Section.
3. Remove the nuts.
4. Remove the fluid cooler tube bracket at the engine.
5. NOTE: Use a backup wrench to hold the case fitting sec ...
Electronic Vibration Analyzer (EVA)
The EVA is a hand-held electronic diagnostic tool which will assist in
locating the source of
unacceptable vibrations. The vibration sensor can be remotely mounted anywhere
in the vehicle for
testing purposes. The unit displays the three most common vibratio ...