Mercedes Vito W639 Wiring Harness Rear Boot Trunk Lid Tailgate Loom A6394405109

Description

Mercedes Vito W639 Wiring Harness Rear Boot Trunk Lid Tailgate Loom is a specialized electrical installation component designed for the rear body section. As part of the Wires, harnesses, and connectors group, it is responsible for a stable electrical connection between the vehicle body and the rear tailgate, ensuring the proper operation of components mounted in the lid. This used component allows for an economical yet technically sound repair of the electrical system in your Mercedes.

Specifications and technical data

• SKU: A6394405109
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A6394405109
• Substitutable numbers: A6394405109, A 639 440 51 09
• Location on the vehicle: Rear
• Category: Wiring Harnesses, Cables & Connectors

Purpose and function of the wiring harness

The presented wiring harness is dedicated to the rear part of the vehicle, in the tailgate area. It is responsible for transmitting signals and power to components located in the lid, such as lighting, the lock, or other electrical receivers provided by the manufacturer. Thanks to the factory-style wire routing and matched connectors, installation is performed at existing mounting points, which reduces the risk of installation damage and eliminates the need for modifications.

Benefits of using an original wiring harness

Using an original wiring harness in the Mercedes Vito W639 allows you to maintain compliance with the vehicle’s factory electrical architecture. The appropriate wire length, correct branching layout, and matched connectors minimize voltage drops and reduce the risk of chafing or short circuits in critical areas, especially in the hinge zone between the body and the tailgate. This solution promotes stable operation of electrical systems and facilitates the diagnosis of potential faults in the future.

Vehicle placement and installation aspects

The wiring harness is designed for installation in the rear of the vehicle, in the tailgate area. The design intended for this location accounts for the movement of the lid, changes in wire positioning, and exposure to bending during daily operation. When replacing, it is recommended to route the wires according to the factory path, use original mounting points, and check the condition of rubber grommets to ensure adequate protection against moisture and mechanical damage.

Application in service practice

The tailgate wiring harness in the Mercedes Vito W639 is often replaced in cases of problems with rear lighting, the central locking of the lid, or intermittent electrical system errors. Choosing a used, functional component allows you to reduce repair costs while maintaining compliance with factory standards. This solution is particularly beneficial for vehicles in intensive use, where quick restoration of full functionality within a rational service budget is a priority.

Expanding electrical system upgrades

If you are planning a comprehensive repair or upgrade of the rear electrical system in your Mercedes and need other elements from the same group, such as additional wire sections, harness branches, or compatible connectors, check the available parts in the Mercedes Wires, harnesses, and connectors category.

Practical tips for vehicles with used components

When working with used electrical installation elements, it is worth paying attention to the condition of the insulation, the absence of signs of overheating, and the secure seating of connectors. It is good practice to perform circuit continuity measurements before installation and to check the correct routing of the harness after closing and opening the tailgate. For drivers who are also considering replacing other components in the vehicle, guide materials may be helpful – when planning major repairs, it is worth reaching for proven sources of knowledge, such as the step-by-step guide to buying a used engine, which shows what to look for when choosing key components.