Ford Focus Mk3 Window Regulator Motor Lifter Rear Right O/S BM51-A27000-BA

Ford Focus Mk3 Window Regulator Motor Lifter Rear Right O/S is a factory-original component from the Window regulators and motors group, designed for operating the rear right window in the vehicle body. The integrated mechanism with an electric drive ensures stable window operation, precise guidance, and convenient control via the vehicle's electrical system.

Specifications and technical data

• SKU: BM51-A27000-BA
• Mark: Ford
• Condition: Used
• OEM Part Number: BM51-A27000-BA
• Substitutable numbers: BM51-A27000-BA, BM51A27000BA, 1870371, BM51-A27000-BE, BM51A27000BE
• Location on the vehicle: Rear, Right
• Part type: Regulator & Motor Assembly
• Category: Window Motors & Regulators

Purpose and function in the vehicle

The presented window regulator with motor is dedicated for installation in the rear right part of the Ford Focus Mk3 body. It is responsible for the smooth raising and lowering of the window, working in conjunction with the factory switches and the car's electrical system. Using a complete mechanism assembly with a drive reduces the risk of mismatch and facilitates servicing. This component is particularly important in cases of symptoms such as slow window operation, stopping halfway, lack of response to the button, or noticeable skipping of the mechanism. Replacing the complete assembly allows for restoring proper functionality without the need to interfere with individual sub-components.

Construction of the window regulator assembly

The window regulator with motor is a mechanical-electrical assembly in which guides, cables, and mounting elements work with an electric drive. This solution ensures:

• stable window guidance throughout the entire range of motion,
• proper transmission of torque from the motor to the lifting mechanism,
• possibility of integration with the factory window control system in the vehicle,
• maintenance of the correct window operating geometry relative to the seals and door frame. Thanks to the use of an original design intended for Ford, the mounting points and geometry are maintained in accordance with factory body specifications, which facilitates installation and minimizes the risk of improper fitment.

Benefits of using an original window regulator

Using an original window regulator with motor in a Ford Focus Mk3 allows for maintaining the consistency of the door's electrical and mechanical system. Key advantages include:

• factory fitment to the door structure – compatibility with original mounting points,
• proper cooperation with the electrical installation and window controls,
• maintenance of the correct window range of motion and its end positions,
• reduction of noise and vibrations during mechanism operation. For the user, this means predictable window operation, no need for installation modifications, and a lower risk of repeated service intervention in the short term.

Part selection by numbers and integration with other components

The window regulator with motor should be selected based on the manufacturer's markings and the location on the vehicle to ensure full compatibility with a specific body version. Proper selection is particularly important when distinguishing between vehicle sides and axles (front/rear), as structural differences affect window operating geometry and mounting methods. If you want to deepen your knowledge about the safe selection of used drive and control components in a car, including the importance of OEM numbers and verification procedures, it is worth reading the expert guide Why it is worth buying used gearboxes and engines – facts instead of myths, which discusses practical principles of identifying parts by numbers and real operational aspects.

Expanding the window control system in a Ford

If you are planning a comprehensive repair or upgrade of the door and window zone in your Ford and need other elements from the same group, such as additional window motors, complete lifting mechanisms, or electric regulators, check the available parts in the Ford window regulators and motors category.