For 1990-2009 cars

Step | Action | Yes | No
--- | --- | --- | ---
1 | Did you perform the Horns Diagnostic System Check? | Go to Step 2 | Go to Diagnostic System Check - Horns
2 | Depress the horn switch. Does the horn have a harsh tone or buzzing? | Go to Step 3 | Go to Symptoms - Horns
3 |

1. Test the horn mounting hardware for adequate torque. The hardware should be tightened to 10 N·m (7 lb ft).
2. Inspect the horn for debris in the joint where the horn attaches to the vehicle.

Did you find and correct the condition?

Go to Step 7

Go to Step 4

4 |

1. Disconnect the horn assembly.
2. Connect a 15 amp fused jumper wire between the positive battery terminal and the control terminal of the horn assembly.
3. Connect another jumper wire between the negative battery terminal and the ground terminal of the horn assembly.

Does the horn assembly have a harsh tone or buzzing?

Go to Step 6

Go to Step 5

5 | Repair the high resistance in the horn control circuit or the horn ground circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 7 | --
6 | Replace the horn. Refer to Horn Replacement . Did you complete the replacement? | Go to Step 7 | --
7 | Operate the horn. Does the horn operate properly? | System OK | Go to Step 1