Ford Focus Mk3 Door Window Lifter Regulator Rear Left N/S BM51-A27001-AA

Ford Focus Mk3 Door Window Lifter Regulator Rear Left N/S is a component from the Window regulators and motors category, designed for operating the rear left window in the vehicle body. The original Ford design ensures proper window guidance, stable mechanism operation, and compatibility with factory mounting points, which facilitates installation and subsequent use.

Specifications and technical data

• SKU: BM51-A27001-AA
• Mark: Ford
• Condition: Used
• OEM Part Number: BM51-A27001-AA
• Substitutable numbers: BM51-A27001-AA, BM51A27001AA
• Location on the vehicle: Rear, Left
• Part type: Window Regulator
• Category: Window Motors & Regulators

Purpose and function in the vehicle

The window regulator used on the rear left side of the body is responsible for the smooth raising and lowering of the window in the rear passenger door. A correctly selected component guarantees:

• stable window guidance in the tracks,
• proper cooperation with the factory control motor,
• maintenance of door sealing thanks to proper window closure,
• comfortable operation from the window control panel. Thanks to being matched to the specific Ford Focus Mk3 body model, the mechanism operates within the range intended by the manufacturer, without the need for modifications or adaptations.

Construction and fitment for Ford Focus Mk3

The regulator is constructed as a complete unit mounted in the inner part of the door, in the area of the rear left window. The arrangement of mounting points and the geometry of the guides are consistent with Ford's factory specifications, which translates into:

• easy positioning relative to mounting holes,
• proper tension of cables or guide elements,
• correct cooperation with a window of standard shape and thickness. Such a fit reduces the risk of jamming, uneven window movement, or excessive load on the electrical system.

Benefits of using an original window regulator

Using a regulator dedicated to the Ford Focus Mk3 for the rear left side allows for maintaining the factory operating parameters of the window system. In practice, this means:

• consistent cooperation with the electrical system and comfort control,
• maintaining the window movement speed intended by the manufacturer,
• lower risk of overloads and failures compared to random replacements,
• maintaining the appropriate level of interior soundproofing and sealing. This solution is particularly beneficial for repairs where the goal is to maintain the original operating characteristics of the windows and compatibility with other door components.

Using a used part in the window system

A used window regulator can be an effective solution for repairing the window lifting system, especially when the priority is cost optimization while maintaining the original design. In the case of mechanical and electromechanical components, such as window regulators, it is important to:

• maintain factory geometry and mounting points,
• ensure compatibility with the original vehicle control system,
• allow for direct installation without modifying the wiring. When selecting parts, it is helpful to compare manufacturer markings and mounting parameters to ensure full compatibility with the specific version of the Ford Focus Mk3.

Ford window regulators and motors – expansion and service

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

Technical support and selection of used parts

When planning a wider range of repairs using used components, it is worth learning the principles of their selection and the real cost differences compared to new subassemblies. A detailed discussion of this topic, along with identification procedures based on manufacturer markings and practical examples, can be found in the article Why it is worth buying used gearboxes and engines – facts instead of myths. The knowledge from this guide helps in making informed decisions also when purchasing other elements, such as window regulators. If you are planning a more extensive vehicle repair and want to select various original used components in one place, practical tips on completing your assortment can be found in the material Comprehensive supply: From engine to the smallest clip – how to complete used car parts in one place?, which discusses the advantages of the One-Stop-Shop approach and how to avoid random replacements.