Mercedes W639 Fuse Box Relay Control Unit Electric Module SAM A6395450301

Visual condition of the part

The product shows signs of use visible in the photos.

Mercedes W639 Fuse Box Relay Control Unit Electric Module SAM is a central component managing power supply and electrical functions in the vehicle, responsible for, among other things, power distribution and circuit protection via integrated fuses. This original module from the Fuses and fuse boxes category ensures stable operation of the electrical system, reducing the risk of failures and overloads. It is a solution designed for users expecting factory compatibility and predictable performance of comfort systems in the Mercedes W639.

Specifications and technical data

• SKU: A6395450301-1
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6395450301
• Substitutable numbers: A6395450301, A 639 545 03 01, A6395450101, A 639 545 01 01, A6395450601, A 639 545 06 01
• Category: Fuses & Fuse Boxes

The role of the SAM comfort module in the electrical system

The Mercedes W639 Fuse Box Relay Control Unit Electric Module SAM acts as a power distribution hub and a control center for many body circuits. It is responsible for logical load management, control of selected consumers, and supervision of circuits protected by fuses. Thanks to this, individual vehicle systems – such as lighting, selected comfort functions, or additional equipment – receive stable power and are protected against short circuits.

A properly selected module from this group allows for restoring the correct operation of the system after damage resulting from overloads, contact corrosion, or previous electrical repairs. Using an original solution is particularly important in vehicles where compliance with the factory wiring architecture and control logic is essential.

Compatibility and selection by part numbers

The presented comfort module for Mercedes should be selected primarily based on the OEM part number and available interchangeable numbers to ensure full compatibility with the specific equipment version and vehicle model year. In practice, this means matching it both in terms of functionality and in terms of connectors, pin layout, and the configuration of circuits protected by fuses.

When selecting components from the power supply and circuit protection group, it is worth paying attention to compatibility with the original installation to avoid communication problems in the vehicle network and errors in the operation of comfort systems. In case of doubt, comparing the markings on the housing and consulting service documentation is helpful.

If you want to deepen your knowledge on verifying component compatibility by numbers, a practical guide may be useful: Shopping for parts online without risk – 5 proven ways to verify component compatibility by OEM numbers and paint codes.

Characteristics of the used module

The offered item comes from the Fuses and fuse boxes category and is marked as used, which in practice means that it was previously operated in a vehicle. Such components are often chosen as an economical alternative to new parts, especially in the case of complex electronic modules where structural and software compatibility is key.

Before installation, a standard service procedure is recommended: checking the condition of the connectors, verifying any signs of overheating, and checking for proper operation in the vehicle after installation. A properly selected and functional module allows for restoring the stability of the electrical system without the need for interfering with wiring harnesses or additional modifications.

Application in service practice

Mercedes W639 Fuse Box Relay Control Unit Electric Module SAM is particularly useful in situations where the vehicle experiences recurring power supply problems for selected circuits, random loss of comfort functions, or damage within the fuse box. Replacing the complete module often shortens the time of diagnostics and repair compared to attempts to regenerate damaged paths or sockets.

This element fits well into standard service procedures used in Mercedes vehicles, enabling consistency with factory documentation and electrical diagrams. It is a solution preferred both by workshops specializing in the brand and by conscious users who take care of the condition of the installation themselves.

Expanding the power system in a Mercedes

If you are planning a comprehensive repair or upgrade of the power supply and electrical circuit protection zone in your Mercedes and need other elements from the same group, such as additional boxes, fuse inserts, or power distribution modules, check the available parts in the Mercedes Fuses and fuse boxes category.