Mercedes Vito Viano W639 Wiper Motor Rear Window Tailgate Actuator A6398200408

Mercedes Vito Viano W639 Wiper Motor Rear Window Tailgate Actuator is a precision component of the rear window cleaning system, designed for installation in Mercedes vehicles. It enables stable, uniform operation of the rear wiper, which translates into better visibility and safer maneuvering in difficult weather conditions. This is a solution for users looking for a proven, technically matched component from the Wiper motors and linkages category.

Specifications and technical data

• SKU: A6398200408
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6398200408
• Substitutable numbers: A6398200408, A 639 820 04 08, KD
• Location on the vehicle: Rear
• Category: Wiper Linkages, Transmissions & Motors

Purpose and function of the rear wiper motor

The presented motor is responsible for driving the rear wiper in the Mercedes W639 series, ensuring the proper torque and smooth movement of the arm across the glass. Its location at the rear of the vehicle allows for direct power transmission to the wiper mechanism, which reduces energy loss and improves operating efficiency. Thanks to appropriately selected electrical and mechanical parameters, the component works with the vehicle's factory installation, maintaining the original operating characteristics of the system.

Benefits of using the original motor in the Mercedes W639

Using a dedicated rear wiper motor in the Mercedes W639 allows you to maintain the consistency of the entire window cleaning system. Proper fitment to the mounts, tailgate geometry, and factory controls minimizes the risk of malfunction, noise, or excessive vibration. The user gains:

• stable wiper operation at various speeds,
• proper interaction with the vehicle's electrical system,
• preservation of factory control logic (intervals, continuous operation),
• assembly consistency with the original wiper arm and mechanism.

As a result, the rear window cleaning system remains functional and predictable, which is important both in daily use and during technical inspections.

Assembly and operational characteristics

The motor has been designed for installation in the rear part of the body, in the immediate vicinity of the wiper mechanism. This placement limits the length of intermediate elements and improves the durability of the entire system. The design, intended for use with factory mounting points, facilitates the mechanic's work and shortens replacement time. In practice, this means:

• no need for modifications to mounts or electrical wiring,
• easier diagnostics during future inspections,
• preservation of original cable and harness routing.

As an element from the Wiper motors and linkages group, the motor works with other system components, such as arms, joints, or levers, creating a coherent system responsible for cleaning the rear window.

Product condition and practical application

The offered rear wiper motor is a used part, which is a beneficial solution for users looking for a reasonable compromise between cost and functionality. This type of component is particularly useful in situations where the existing wiper drive has suffered mechanical or electrical damage, manifesting as the arm stopping in random positions, lack of response when switched on, or uneven operation. Replacing it with a functional motor restores proper system operation and improves driving comfort in rain, snow, or when driving on dirty roads.

Related categories and technical materials

If you are planning a comprehensive repair or modernization of the rear window area in your Mercedes and need other elements from the same group, such as drives, gears, or wiper linkages, check the available parts in the Mercedes wiper motors and linkages category.

If you are interested in a broader context of vehicle operation and want to better understand how failures of key components can affect your service budget, it is worth reading an article describing problematic engines in a popular model of the Bavarian brand: Faulty BMW E90 engines: check what can ruin your budget!

To learn how a wide selection of components in one place can shorten vehicle downtime at the mechanic and facilitate the selection of appropriate used parts, you can also refer to the material: how a wide assortment in one warehouse shortens vehicle downtime at the mechanic.