Operation CHARM: Car repair manuals for everyone.

Test A: The Horn Is Inoperative

PINPOINT TEST A: THE HORN IS INOPERATIVE

Normal Operation
The smart junction box (SJB) supplies the switched and control voltage to the horn relay (part of the SJB). When the horn switches (part of the steering wheel) are pressed, the switches are grounded to the steering wheel through circuit GD165 (BK), and the clockspring to the instrument panel cross-car beam through circuit GD116 (BK/VT). Ground is then supplied to the horn relay through circuit CRH02 (BU/WH), energizing the horn relay. The horn relay then sends voltage to the horn through circuit CRH04 (VT/GN), enabling the horn to sound. Ground for the horn is supplied through circuit GD123 (BK/GY).

This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- Horn
- Clockspring
- Steering wheel switch harness
- Horn switches (part of the steering wheel)
- SJB


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