The horn is the most popular device for inter-vehicle communication. They can be used to signal danger, get attention, or a common favorite, voice frustration in traffic.
How does the horn work?
Most passenger vehicle horns are electrically powered, and mounted near the inside of the front bumper. When the horn button is pressed, electricity is allowed to flow through the horn circuit, through the fuse and relay, and into the horn. Once there the electricity is converted to sound waves, and the horn sounds.
What are the symptoms related to a bad horn?
Failure of the horn will simply result in loss of horn functionality, or a weak horn sound being emitted.
Can I drive with a horn problem?
A failed or ailing horn should not affect any other components. However, horns are legally required safety features, and may cause the vehicle to fail a safety inspection if inoperable.
How often do horns need to be replaced?
Horns rarely fail on newer vehicles, as they have no moving parts. A frontal collision, or salt and water intrusion from inclement weather are more likely to cause the horn to fail than age.
How are horn issues diagnosed?
When the horn stops working, most technicians will immediately grab their test light, or voltmeter, and see where voltage is not present in the circuit. The technician should check the fuse, identify that the horn switch in the steering wheel is sending power through the circuit, and ensure the horn is receiving power. If the technician gets to the horn, and finds proper voltage at the horn when the horn switch is pressed, the horn will be inspected. If the horn is receiving power, and the connection is not corroded or dirty, then the horn will be replaced. If needed, the connection can be cleaned, and retested.
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How is a horn replaced?
In most cases replacing a horn will involve unbolting the horn, and disconnecting an electrical connector. However, there are many situations where the horn is installed in an obstructed location, and body panels may need to be removed to gain access.
RepairPal Recommendations for horn issues
Some aftermarket horns may not be legal in your area. Check with local codes before purchasing a horn with unusual sound or volume.
What to look out for when dealing with horn issues
Horns on most vehicles are small and can be placed in inconspicuous and hard to reach locations.
Can I replace the horn myself?
Diagnosing and replacing the horn could be a fun morning project for any DIYer. This job does not typically require many tools, and the only knowledge needed is understanding how to test a basic circuit. If the process seems totally unclear, trusting a technician with the repair is always an effective option.
Mercedes-Benz Horn Replacement Cost Estimates
The average cost for a Horn Replacement is between $185 and $214 but can vary from car to car.