Test B: The Horn Is Always On

PINPOINT TEST B: THE HORN IS ALWAYS ON

B1-B7:

Normal Operation
The horn relay control voltage and switched voltage circuits are supplied by the battery junction box (BJB) through circuit 1680 (OG/RD). The horn relay is controlled through circuit 1 (DB) by the horn switch. When the horn switch is pressed, the horn relay control circuit 1 (DB) is grounded through the clockspring to the vehicle harness. The lighting control module (LCM) also supplies a ground to the horn relay through circuit 1 (DB) for the anti-theft function. The LCM supplies a momentary ground to the horn relay through circuit 1 (DB) to indicate the anti-theft system is armed, and an on then off ground when an intrusion is detected. The horn relay is then energized causing voltage to be applied to circuit 6 (YE/LG), enabling the horn to sound.

Possible Causes
- circuit 1 (DB) short to ground
- circuit 6 (YE/LG) short to voltage
- horn relay
- LCM
- clockspring
- horn switch (part of the driver air bag module)
- steering wheel switch harness