2010 BMW 335i Horn Replacement Cost

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.

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.

Failure of the horn will simply result in loss of horn functionality, or a weak horn sound being emitted.

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.

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.

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.