Ford Focus St-2 Mk2 Alternator 120A 14V 2.5 Petrol Manual 3M5T-10300-JC 1684865

Ford Focus St-2 Mk2 Alternator 120A 14V 2.5 Petrol Manual is an efficient charging system component designed for use with a petrol engine and a manual transmission. It is responsible for providing a stable power supply to the vehicle's electrical system and charging the battery under the demanding conditions of dynamic driving characteristic of the ST version.

Specifications and technical data

• SKU: 1684865
• Mark: Ford
• Condition: Used
• OEM Part Number: 1684865
• Substitutable numbers: 1684865, 3M5T-10300-JD, 3M5T10300JD
• Fuel type: Petrol
• Gearbox type: Manual
• Category: Alternators & Generators

Purpose and operating parameters

The presented alternator belongs to the Alternators and generators group and has been designed for a petrol-powered drivetrain paired with a manual transmission. A current output of 120A at 14V provides sufficient power headroom for factory electrical equipment and additional consumers, such as advanced audio systems or onboard accessories.

The operating characteristics of the alternator are tailored to the specifics of the 2.5 petrol unit, which translates into stable charging across the entire rev range – from city driving to the intense acceleration typical of the ST-2 Mk2 version.

Benefits of using the alternator in the Ford Focus St-2 Mk2

Using this alternator model allows for maintaining the proper energy balance of the vehicle, which has a direct impact on:

• reliable engine starting thanks to a properly charged battery,
• stable power supply for control units, sensors, and safety systems,
• uninterrupted operation of lighting, air conditioning, and comfort equipment,
• reduced risk of voltage drops under high electrical load.

For the ST-2 Mk2 version, where the full potential of the engine is often utilized, a functional alternator with appropriate output is crucial for the reliability of the entire electrical system.

Product characteristics and installation

The alternator is a dismantled part, which allows for an economical replacement while maintaining proper operating parameters. The design, intended for a specific petrol engine and manual transmission configuration, facilitates fitting to the engine's factory equipment.

In practice, this means:

• maintaining compatibility with factory mounting and belt drive systems,
• proper cooperation with the vehicle's electrical installation,
• the ability to use existing connection points without modifications.

As a result, the alternator can be installed in a predictable and repeatable manner, which is important for both workshops and users servicing the vehicle themselves.

Part number usage and identification

The product has a dedicated OEM part number and associated interchangeable numbers, which facilitates unambiguous identification in service catalogs and parts selection systems. In practice, this allows for quick verification of compatibility with a specific Ford Focus ST-2 Mk2 configuration, minimizing the risk of selecting the wrong alternator.

Information such as SKU, brand designation, and condition is also available in the product description, which further supports the process of selection and comparison with other charging system components.

If you are planning a comprehensive repair or upgrade of the charging system area in your Ford and need other items from the same group, such as alternators with different outputs, generators, or related mounting components, check the available parts in the Ford Alternators and generators category.

For drivers who are simultaneously diagnosing disturbing noises from the suspension or planning a wider range of service work, an article discussing the causes of knocking and the possibilities of using dismantled parts may be helpful – more information can be found in the material on effective removal of suspension knocking and repair cost optimization.