Mercedes Vito Viano W639 Headlight Switch Unit Button Knob A6395450104

Visual condition of the part

The product shows signs of use visible in the photos.

Mercedes Vito Viano W639 Headlight Switch Unit Button Knob is an original component from the Switches, control elements and ignition locks group, designed for operating the lighting in the driver's cabin. This used module ensures a factory-fit to the electrical system, maintaining the proper ergonomics and control logic known from the W639 series Vito and Viano models.

Specifications and technical data

• SKU: A6395450104-1
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6395450104
• Substitutable numbers: A6395450104, A 639 545 01 04
• Category: Switches & Controls

Function and application

This switch is responsible for controlling the vehicle's main lighting modes, such as parking lights, low beams, or automatic mode – depending on the specific equipment version configuration. The button and knob assembly has been designed by the manufacturer for intuitive operation, making it easy to quickly switch functions without taking your eyes off the road.

Thanks to a design consistent with factory Mercedes standards, the module works with the electrical system and lighting monitoring systems in a predictable and stable manner. This solution is particularly beneficial when replacing a damaged factory switch with a component of the same origin.

Construction and control ergonomics

The unit combines the function of a rotary knob and a button, allowing for a compact arrangement of several operating modes in one easily accessible place on the dashboard. The shape and resistance of the knob are adapted for daily use, providing tactile switching positions and a secure grip.

The layout of the pictograms and the operation of the button are consistent with the rest of the Mercedes Vito and Viano cockpit, which helps the driver maintain existing operating habits. This type of solution reduces the risk of errors when changing lighting modes, especially at night.

Benefits of using an original switch

Using an original light switch in a Mercedes Vito or Viano allows you to maintain consistent operation with the vehicle's other systems. This is particularly important in the case of integration with comfort modules, burnt bulb monitoring, or additional lighting functions that require specific control signal characteristics.

A used element of this type represents a reasonable compromise between repair costs and maintaining factory build quality. Original Mercedes components are designed for long-term use, so with proper installation, they can continue to work stably in the vehicle's electrical system.

Part selection and compatibility

When selecting a light switch for a Vito or Viano W639, it is crucial to match it to the specific equipment version and vehicle model year. It is worth paying attention to the lighting function configuration in the car to maintain full compatibility with the installation and control panels in the cabin.

If you are planning a comprehensive repair or upgrade of the lighting control zone in your Mercedes and need other elements from the same group, such as additional buttons, control modules, or ignition lock elements, check the available parts in the Mercedes switches, control elements and ignition locks category.

Used Mercedes parts – when is it worth it?

For Mercedes-class vehicles, choosing a used, original light switch is often a cost-effective solution, especially when you want to maintain factory specifications without incurring the costs of new components. It is worth learning the broader context of using original parts from disassembly – it is discussed in the article Used parts for Mercedes – original parts from disassembly, which explains how to safely use such solutions in service and operation.