Mercedes W221 Horn Signal Alarm Siren High Pitch Tone Right O/S A0055422020

Mercedes W221 Horn Siren Alarm High Tone Right is an original part from the Horns category, designed for the right side of the vehicle. It provides a clear, high warning tone, improving road safety and communication in W221 generation S-Class models. This is a practical solution for users who expect stable operation of the factory sound signaling system.

Specifications and technical data

• SKU: A0055422020
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A0055422020
• Substitutable numbers: A0055422020, A 005 542 20 20
• Location on the vehicle: Right
• Category: Horns

Horn Purpose and Function

The presented horn is designed as part of the sound signaling system on the right side of the body in the Mercedes S-Class W221. It is responsible for generating a high warning tone, which complements the second horn in the vehicle, creating a clear and audible signal for other road users. Using the correct part in this location is crucial for maintaining the proper volume and sound characteristics intended by the manufacturer.

Construction and Fit for Mercedes W221

The horn has been developed specifically for the W221 platform, ensuring its geometry, mounting, and electrical connector are adapted to the factory installation. Proper placement on the right side of the vehicle allows for:

• correct sound propagation in front of the vehicle,
• stable mounting at the designated structural point,
• seamless connection to the existing wiring harness.

This precise fit minimizes the risk of incorrect installation and eliminates the need for wiring modifications, which is particularly important for premium vehicles.

Operating Characteristics and Application

The high-tone alarm siren plays a key role in both the daily use of the horn and the operation of the factory alarm system. A correctly selected part ensures:

• a clear, high warning sound signal,
• sound consistency with the second horn in the vehicle,
• stable operation under typical road conditions.

This allows the sound signaling system in the Mercedes W221 to maintain parameters close to factory specifications, which is important for both user comfort and safety.

Condition, Verification, and Installation

The part is offered as a used part, allowing for an economical repair of the signaling system while maintaining the original construction. Before installation, standard verification of the vehicle's electrical system and ground points is recommended to ensure proper horn power supply. Installation involves screwing the horn into its designated place on the right side and connecting the factory connector, which in most cases does not require additional modifications.

Horn Selection by Numbers and Compatibility

The offered horn is a Mercedes brand part, assigned to a specific manufacturer's reference and having interchangeable numbers, which facilitates part selection based on service documentation or catalogs. When replacing, it is advisable to compare the markings on the old part with the data in the specifications to confirm compatibility with your W221 model. This approach minimizes the risk of purchasing an incompatible component and speeds up the repair process.

If you are planning a comprehensive repair or upgrade of the sound signaling area in your Mercedes and need other parts from the same group, such as low-tone sirens, additional sound signals, or horn control modules, check the available parts in the Mercedes Horns category.

To better understand the structural differences between S-Class generations and the specifics of selecting parts like horns, it is worth reading the article Evolution of the Mercedes S-Class: from W140 to W222 – Innovations, Model Differences, and Mercedes Auto Parts Over the Years, which discusses key technical changes and practical service tips.