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Diagnosis and Testing|Removal and Installation > < 413-06 Horn|Specifications

Mondeo 2001 (10.2000-02.2007)

Horn - Horn Mondeo 2001 (10/2000-02/2007)
Diagnosis and Testing

Refer to Wiring Diagrams Section 413-06, for schematic and connector information.

Inspection and Verification

  1. Verify the customer concern.
  1. Visually inspect for obvious signs of electrical damage.

Visual Inspection Chart

Electrical
  • Fuse(s)
  • Wiring harness
  • Electrical connector(s)
  • Horn(s)
  • Relay
  • Horn switch
  • Clock spring
  1. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
  1. If the cause is not visually evident, verify the symptom and refer to the Symptom Chart.

Symptom Chart

Symptom Chart

Symptom Possible Sources Action
The horn does not sound
*
Fuse(s).
*
Circuit(s).
*
Horn(s).
*
Horn switch.
*
Clock spring.
*
Horn relay.
*
GO to Pinpoint Test ??.
The horn sounds continuously
*
Circuit(s).
*
Horn switch.
*
Clock spring.
*
Horn relay.
*
GO to Pinpoint Test ??.

Pinpoint Tests

NOTE:
NOTE:Use a digital multimeter for all electrical measurements.

PINPOINT TEST A : THE HORN DOES NOT SOUND
TEST CONDITIONS DETAILS/RESULTS/ACTIONS
A1: CHECK THE OPERATION OF THE HORN RELAY
1
Press the horn switch and listen for the horn relay clicking.

Does the horn relay click when the horn switch is pressed?
Yes
GO to A8.
No
GO to A2.
A2: CHECK THE HORN SWITCH OPERATION
1
Disconnect Horn Relay C903.
2
Press and hold the horn switch.

3
Measure the resistance between horn relay C903 pin 1, circuit 31S-GJ7 (BK), harness side and ground.
4
Release the horn switch.

Is the resistance less than 5 ohms?
Yes
GO to A3.
No
GO to A4.
A3: CHECK FOR VOLTAGE AT HORN RELAY

1
Measure the voltage between horn relay C903 pin 2, circuit 30-GJ7 (RD), harness side and ground; and between the horn relay C903 pin 5, circuit 30-GJ8 (RD), harness side and ground.

Are the voltages greater than 10 volts?
Yes
CARRY OUT the relay Component Test. REFER to the wiring diagrams. INSTALL a new horn relay as necessary. TEST the system for normal operation.
No
INSTALL a new battery junction box (BJB). TEST the system for normal operation.
A4: CHECK CIRCUIT 31S-GJ7 (BK/BU) FOR SHORT TO GROUND
WARNING:
WARNING:To deactivate the air bag module, refer to the procedure in Section 501-20B for the correct air bag module deactivation procedure. Failure to follow this instruction may result in personal injury.
1
Remove the driver air bag module. REFER to Section  501-20A Safety Belt System / 501-20B Supplemental Restraint System.
2
Disconnect Clock Spring C413.

3
Measure the resistance between clock spring C413 pin 4, circuit 31S-GJ7 (BK/BU), harness side and ground.

Is the resistance less than 5 ohms?
Yes
REPAIR the circuit. TEST the system for normal operation.
No
GO to A5.
A5: CHECK THE CLOCK SPRING
1
Disconnect Horn Switch C4.

2
Measure the resistance between horn switch C4 pin 1, harness side and ground.

Is the resistance greater than 10,000 ohms?
Yes
GO to A6.
No
INSTALL a new clock spring. REFER to Section  501-20A Safety Belt System / 501-20B Supplemental Restraint System. TEST the system for normal operation.
A6: CHECK THE HORN SWITCH
1
Disconnect Horn Switch C5.

2
Measure the resistance between horn switch C5 pin 1, component side and ground.

Is the resistance greater than 10,000 ohms?
Yes
INSTALL a new horn switch.
REFER to Horn Switch in this section.
TEST the system for normal operation.
No
GO to A7.
A7: CHECK GROUND CIRCUIT 31-GJ9 (BK)

1
Measure the resistance between clock spring C413 pin 3, circuit 31-GJ9 (BK), harness side and ground.

Is the resistance less than 5 ohms?
Yes
INSTALL a new clock spring. REFER to Section  501-20A Safety Belt System / 501-20B Supplemental Restraint System. TEST the system for normal operation.
No
REPAIR the circuit. TEST the system for normal operation.
A8: CHECK THE HORN GROUND CIRCUIT
1
Disconnect Horn Relay C903.

2
Measure the resistance between horn relay C903 pin 3, circuit 29S-GJ6 (OG/YE), harness side and ground.

Is the resistance between 0.5 and 4 ohms?
Yes
GO to A9.
No
GO to A10.
A9: CHECK VOLTAGE AT HORN RELAY

1
Measure the voltage between horn relay C903 pin 5, circuit 30-GJ8 (RD), harness side and ground.

Is the voltage greater than 10 volts?
Yes
CARRY OUT the relay Component Test. REFER to the wiring diagrams. INSTALL a new horn relay as necessary. TEST the system for normal operation.
No
INSTALL a new battery junction box (BJB). TEST the system for normal operation.
A10: CHECK CIRCUIT 29S-GJ6 (OG/YE) FOR OPEN
1
Disconnect Horn C151.

2
Measure the resistance between horn relay C903 pin 3, circuit 29S-GJ6 (OG/YE), harness side and the horn C151 pin 2, harness side.

Is the resistance less than 5 ohms?
Yes
GO to A11.
No
REPAIR the circuit. TEST the system for normal operation.
A11: CHECK THE HORN GROUND CIRCUIT

1
Measure the resistance between horn C151 pin 1, circuit 31-GJ6 (BK), harness side and ground.

Is the resistance less than 5 ohms?
Yes
INSTALL a new horn. TEST the system for normal operation.
No
REPAIR circuit 31-GJ6 (BK). TEST the system for normal operation.

PINPOINT TEST B : THE HORN SOUNDS CONTINUOUSLY
TEST CONDITIONS DETAILS/RESULTS/ACTIONS
B1: CHECK CIRCUIT 29S-GJ6 (OG/YE) FOR SHORT TO (B+)
1
Disconnect Horn Relay C903.

Does the horn stop when the relay is disconnected?
Yes
GO to B2.
No
REPAIR the circuit. TEST the system for normal operation.
B2: CHECK CIRCUIT 31S-GJ7 (BK)

1
Measure the resistance between horn relay C903 pin 1, circuit 31S-GJ7 (BK), harness side and ground.

Is the resistance greater than 10,000 ohms?
Yes
CARRY OUT the relay Component Test. REFER to the wiring diagrams. INSTALL a new horn relay as necessary. TEST the system for normal operation.
No
GO to B3.
B3: CHECK CIRCUIT 31S-GJ7 (BK/BU) FOR SHORT TO GROUND
WARNING:
WARNING:To deactivate the air bag module, refer to the procedure in Section 501-20B for the correct air bag module deactivation procedure. Failure to follow this instruction may result in personal injury.
1
Remove the driver air bag module. REFER to Section  501-20A Safety Belt System / 501-20B Supplemental Restraint System.
2
Disconnect Clock Spring C413.

3
Measure the resistance between horn switch C413 pin 4, circuit 31S-GJ7 (BK/BU), harness side and ground.

Is the resistance greater than 10,000 ohms?
Yes
GO to B4.
No
REPAIR the circuit. TEST the system for normal operation.
B4: CHECK THE CLOCK SPRING
1
Disconnect Horn Switch C4.

2
Measure the resistance between horn switch C4 pin 1, circuit 31S-GJ9 (BK), component side and ground.

Is the resistance greater than 10,000 ohms?
Yes
INSTALL a new clock spring. REFER to Section  501-20A Safety Belt System / 501-20B Supplemental Restraint System. TEST the system for normal operation.
No
INSTALL a new horn switch.
REFER to Horn Switch in this section.
TEST the system for normal operation.

Diagnosis and Testing|Removal and Installation > < 413-06 Horn|Specifications