GM Service Manual Online
For 1990-2009 cars only

System Description

The horn system consists of the following components:

    • The HORN fuse
    • The horn relay
    • The horn brush slip ring
    • The horn switch
    • The horns
    • The remote control door lock receiver

System Operation

The vehicle horns are activated whenever the horn switch is depressed, or when the remote control door lock receiver (RCDLR) commands the horns on. The RCDLR commands the horns on when the keyless entry system is used to lock the vehicle, a horn chirp may sound to notify the driver the vehicle has been locked. For further information, refer to Keyless Entry System Description and Operation in Keyless Entry.

Circuit Operation

Battery positive voltage is applied at all times to the horn relay coil and the horn relay switch. Pressing the horn switch applies ground to the horn relay control circuit. The RCDLR may also apply ground to the horn relay control circuit as described above. When the horn relay control circuit is grounded, the horn relay is energized and battery positive voltage is applied to the horns through the horn control circuit. The horns sound as long as ground is applied to the horn relay control circuit.