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 control voltage to the horn relay (part of the SJB). When the horn switch (part of the steering wheel) is pressed, the switch closes and ground is applied from the steering wheel switch harness through the clockspring to the horn relay through circuit CRH03 (BN). The horn relay is then energized, applying voltage to the horn through circuit SRH01 (YE/RD), enabling the horn to sound. Ground for the horn is supplied through circuit GD120 (BK/GN).

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


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A9: