Mercedes W164 W251 Fuse Box Relay Module Control Unit A1645403772

Mercedes W164 W251 Fuse Box Relay Module Control Unit is an original control unit designed for the electrical systems in vehicles of this series. This component is responsible for stable circuit power supply, installation protection, and relay operation control, which directly impacts the reliability of the onboard electronics. Thanks to the factory Mercedes design, the module ensures a proper fit for the wiring harnesses and electrical architecture of the specific model.

Specifications and technical data

• SKU: A1645403772
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A1645403772
• Substitutable numbers: A1645403772, A 164 540 37 72
• Category: Fuses & Fuse Boxes

Purpose and function in the vehicle

The presented Mercedes W164 W251 Fuse Box Relay Module Control Unit is a component from the Fuses and fuse boxes group, responsible for power distribution and the separation of individual electrical circuits. In a typical configuration, it supports, among others, lighting circuits, comfort systems, selected safety systems, and additional power consumers, providing them with appropriate overcurrent protection.

As an original Mercedes component, the module is designed for the specific electrical architecture of the W164 and W251 series, which reduces the risk of improper fitment, communication errors in the vehicle network, and mechanical installation issues.

Construction and technical aspects

The unit combines fuse sockets, relays, and control electronics in a single housing, allowing for compact installation routing and shorter wiring harnesses. The layout of current paths and contact fields is optimized for current-carrying capacity and heat dissipation, which promotes stable operation of the electrical system over a long service life.

The module is adapted to work with factory Mercedes installation connectors, which enables installation in a plug-and-play manner – after proper coding and configuration in accordance with the manufacturer's service procedures.

Service application and part selection

The component is suitable for replacing a damaged fuse box, repairs after electrical short circuits, or when diagnosing power supply issues for individual circuits. Since the module belongs to the Fuses and fuse boxes group, its replacement is often a key step in resolving faults related to the lack of power to selected vehicle systems.

Before installation, it is recommended to verify compatibility with the specific vehicle equipment version and electrical configuration, as well as to perform computer diagnostics after installation to confirm proper communication with other control units.

Condition and benefits of choosing an original module

The offered item is in used condition, which allows for an economical repair while maintaining the original build quality characteristic of the Mercedes brand. In practice, this means factory-standard fitment with mounting brackets, compatibility with wiring harnesses, and predictable behavior within the vehicle's electrical system.

Choosing an original fuse box and relay module reduces the risk of fitment issues and minimizes the need for installation modifications, which is particularly important in modern vehicles with extensive electronics.

Expanding the electrical system in your Mercedes

If you are planning a comprehensive repair or upgrade of the electrical system area in your Mercedes and need other components from the same group, such as additional boxes, power distribution modules, or housings with sockets, check out the available parts in the Mercedes Fuses and fuse boxes category.