GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 1999 🢒 Grand Prix 🢒 Body and Accessories 🢒 Body Control System 🢒 Diagnostic System Check - Horns

The horn system consists of the following functional components:

    • The HORN fuse
    • The horn switch and slip ring
    • The horn relay
    • The 2 horns
    • Related wiring

Use the following guidelines in order to diagnose a horn system problem:

  1. Verify the owner's complaint.
  2. Inspect for an open HORN fuse.
  3. Replace the horn relay with a known good relay.
  4. Inspect the horn operation.

    5. If the system proves good, replace the horn relay.

  5. Inspect for an aftermarket (non-OEM) equipment.

    6. If add-on accessories are discovered, disconnect the system in order to ensure that the installation of the aftermarket equipment is not the cause of the problem.

  6. Inspect all the connectors and the related wiring to the suspect electrical component.

    7. Inspect for poor mating of the connector halves or terminals not fully seated in the connector body (backed out).

  7. Inspect for dirt or corrosion on the connector terminals.

    8. The terminal must be clean and free of any foreign material which could impede the proper terminal contact.

  8. Inspect the related ground eyelets for a clean and tight connection.

If the horn system problem still exists, refer to the following table:

Step

Action

Normal Result(s)

Abnormal Result(s)*

1
  • Press and release the horn switch.
  • Both of the horns sound. The horns stop sounding when the switch is released.
    •  Horns Inoperative
    •  Horns Always On

* Refer to the appropriate symptom diagnostic table for the applicable abnormal result.