Mercedes ML W166 Window Lifter Regulator Rear Left N/S Door Card Panel

The Mercedes ML W166 Rear Left Door Window Regulator with Trim Mount is an original part from the Window Regulators and Motors group, designed for the rear left window in an SUV body style. It ensures stable window guidance and proper support for the door trim, which translates to reliable operation of the window lifting and lowering mechanism and correct trim panel fitment.

Specifications and technical data

• SKU: A1667300179
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A1667300179
• Substitutable numbers: A1667300179, A 166 730 01 79
• Location on the vehicle: Rear, Left
• Category: Window Motors & Regulators

Vehicle Application and Function

The presented window regulator is dedicated for installation in the rear, left side, of the second-row passenger door. It is responsible for transferring the drive from the adjustment mechanism to the window and for holding it in the correct position within the guides. The integrated trim mount allows for secure attachment of the door trim, reducing unwanted vibrations and noise during driving.

A system configured in this way is particularly important in premium vehicles, where quiet window operation, smooth movement, and precise interior component fitment are expected.

Construction and Technical Features

The regulator belongs to the Window Regulators and Motors group, meaning it works with the door window control system, both in versions with simple controls and with more advanced comfort modules. The design includes:

• a dedicated mount for the internal door structure on the rear left side,
• mounting points for the window ensuring stable guidance throughout its range of motion,
• integrated brackets for trim panel mounting, facilitating correct upholstery seating.

This configuration allows for maintaining the factory window operation geometry and the correct positioning of the trim panel relative to the seals and other interior trim elements.

Benefits of Using an Original Part

Using an original window regulator for the Mercedes ML W166 helps maintain the door's structural integrity and predictable mechanism performance over a long service life. Key advantages include:

• factory fit for the rear left side – no need for modifications or adapter brackets,
• correct compatibility with the existing window control system,
• maintaining proper trim panel mounting rigidity, reducing creaks and looseness,
• easier diagnosis of potential faults due to compliance with factory service documentation.

A used part is a good choice for maintenance repairs when the priority is to combine reasonable costs with the preservation of the original door construction.

Installation and Service Application

The window regulator with trim mount is designed for direct replacement of the factory part. During service work, it is advisable to pay attention to:

• correct positioning of the window in the guides on the rear left side,
• checking the condition of the seals and upholstery mounting points,
• verifying the smoothness of window movement after installation and potential adaptation in the comfort system (if present).

An installation performed in this manner restores proper mechanism operation and user comfort for the rear left window, without compromising interior fitment.

Repair Extension and Technical Knowledge

If you are planning a comprehensive repair or upgrade of the door and window area in your Mercedes and need other parts from the same group, such as guides, lifting mechanisms, or electric drives, check the available parts in the Mercedes Window Regulators and Motors category.

When planning broader service work or comparing design solutions across different makes and models, the guide on common operational issues in popular mid-range cars may also be helpful, such as the article Faulty BMW E90 Engines: Find Out What Can Ruin Your Budget!, which shows how to approach repair costs and diagnostics consciously.