Ford Focus St-2 Mk3 Window Motor Rear Lifter Regulator Left N/S BM51-A27001-BE

Ford Focus St-2 Mk3 Window Motor Rear Lifter Regulator Left N/S is an original component from the Window Regulators and Motors group, designed for precise operation in the rear left window of the vehicle. It ensures stable window guidance, proper drive transmission, and consistent operation of the lifting and lowering mechanism. This is a practical solution for users who want to restore full functionality of the electric window control without compromising on fitment.

Specifications and technical data

• SKU: BM51-A27001-BE
• Mark: Ford
• Condition: Used
• OEM Part Number: BM51-A27001-BE
• Substitutable numbers: BM51-A27001-BE, BM51A27001BE, 1870372
• Location on the vehicle: Rear, Left
• Category: Window Motors & Regulators

Purpose and function in the vehicle

The rear left window regulator in the version dedicated to the Ford Focus ST-2 Mk3 is responsible for the smooth movement of the window in the guides and cooperation with the window control system. Its placement in the rear left part of the body allows for direct replacement of the component without the need for modifications to the electrical installation or door mounts.

As a part from the Window Regulators and Motors group, this component is designed for:

• stable window guidance throughout the entire range of operation,
• correct transmission of torque from the motor to the lifting mechanism,
• maintaining proper tension of the cables or mechanism arms,
• cooperation with factory window control switches.

Advantages of using an original Ford component

Using an original window regulator in the Ford Focus ST-2 Mk3 allows for maintaining the factory operating parameters of the system. Proper fitment to the door and serial mounting points reduces the risk of play, improper window closing, or excessive motor load. As a result, the mechanism operates in a predictable manner, and the user retains the comfort of operating the window via the button.

Key benefits include:

• compatibility with the factory installation – no need for wiring or mount modifications,
• consistency with the operating parameters of other windows in the vehicle,
• reduction of the risk of jamming and uneven window movement,
• easier diagnostics in case of potential system failures.

Assembly and operational characteristics

The regulator is prepared for operation in a specific location on the body, which facilitates installation and subsequent operation. The design intended for the rear left side of the vehicle allows for maintaining the correct geometry of window guidance and proper force distribution in the mechanism. In practice, this translates into even closing, lack of excessive stress, and lower load on other door components.

The element from this group of parts works well both in standard city operation and in conditions of frequent window use, e.g., during intensive driving with passengers in the back seat. Stable mechanism operation reduces noise and minimizes the risk of window damage resulting from improper guidance.

Condition and service application

The offered window regulator is a used part, which makes it an attractive solution for users looking for a technically sound component at a reasonable service price. This type of part fits well into maintenance repairs when the priority is to restore the functionality of the window system while maintaining compliance with factory specifications.

During replacement, it is worth paying attention to:

• the condition of the door mounts and any structural play,
• correct routing of the electrical harness in relation to moving parts,
• proper positioning of the window in the guides after installation.

Ford Window Regulators and Motors – expansion and service

If you are planning a comprehensive repair or modernization of the door area in your Ford and need other elements from the same group, such as window lifting mechanisms, control motors, or complete guide assemblies, check the available parts in the Ford Window Regulators and Motors category.

Technical support and service knowledge

When planning broader service work on the car, it is also worth considering the condition of the powertrain to avoid unforeseen costs. Practical tips on diagnosing problematic power units can be found in the article: BMW E90 engine failures: check what can ruin your budget!. Although it concerns a different brand, it shows how important a conscious approach to service and the selection of used parts is.