Mercedes W166 Door Wiring Loom Harness Cable Front Right O/S A1664403508

Mercedes W166 Door Wiring Harness Cable Front Right O/S is an original, used electrical system component designed for installation in the front right door of vehicles in this series. Thanks to the factory fitment and preserved connector structure, the harness allows for efficient replacement of damaged wiring and restoration of proper door electrical operation, while ensuring stable signal and power connections.

Specifications and technical data

• SKU: RHD-A1664403508
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A1664403508
• Substitutable numbers: A1664403508, A 166 440 35 08
• Location on the vehicle: Front, Right
• Part type: Body Harness
• Category: Wiring Harnesses, Cables & Connectors

Purpose and function in the electrical system

The presented Mercedes W166 Door Wiring Harness Cable Front Right O/S belongs to the Wires, harnesses, and connectors category and is responsible for transmitting power and control signals between the body wiring and the equipment located in the front right door. This includes typical circuits used in this area, such as window control, central locking, or mirror adjustment, depending on the specific vehicle configuration.

The vehicle placement specified as front – right side allows for clear identification of the installation area and reduces the risk of error when selecting the component for the specific side of the body.

Construction, connectors, and installation compatibility

The harness was designed by the vehicle manufacturer as a factory installation element, which translates into:

• the use of dedicated connectors matching the original door modules and equipment,
• appropriately selected wire cross-sections for individual circuits,
• wire routing consistent with the door construction and the grommet between the pillar and the door leaf.

Thanks to this, installation is limited to replicating the factory harness route and plugging the connectors into the designated sockets, without the need for installation modifications or the use of additional adapters.

Practical application and benefits of replacement

Using an original door harness in the front right door allows for solving typical problems resulting from wire damage in the grommet, contact corrosion, or broken conductive cores. Replacing the complete harness is particularly beneficial when:

• there are intermittent power losses to door components,
• module communication errors appear in diagnostics,
• mechanical damage to wires or connectors has occurred.

The original design ensures consistency with the factory electrical diagram, which facilitates service work and future diagnostics, and minimizes the risk of improper door equipment operation.

Characteristics of the used component

The harness comes from disassembly, making it an economical alternative to a new part while maintaining the original manufacturer's specifications. The used component allows for reducing repair costs while maintaining compliance with the factory standard of wire, insulation, and connector construction.

Expanding the installation in a Mercedes vehicle

If you are planning a comprehensive repair or upgrade of the door zone in your Mercedes and need other elements from the same group, such as additional harnesses, wire sections, or installation connectors, check the available parts in the Mercedes Wires, harnesses, and connectors category.

For users interested in a broader approach to servicing premium cars using original parts from disassembly, valuable tips on cost optimization and selecting proven components can be found in the article Luxury within reach – how to service a legendary Porsche brand using proven used parts.