BMW E90 E91 E92 E93 LCI Diesel N57 Alternator 150A 7808073 7805432

BMW E90 E91 N57 Alternator Generator Diesel 150A 7808073 is an original part from the Alternators and Generators group, designed for BMW 3 Series diesel engines with the N57 unit. The used generator ensures stable charging of the electrical system, providing a functional service solution for vehicles powered by Diesel fuel.

Specifications and technical data

• SKU: 7808073
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 7808073
• Substitutable numbers: 12317808073, 7808073, 7805432, 12317805432
• Fuel type: Diesel
• Category: Alternators & Generators

Purpose and Function in the Electrical System

The alternator in the N57 engine is responsible for converting mechanical energy from the crankshaft into electrical energy, powering all consumers in the vehicle and charging the battery. In the 150A version, it is adapted to the typical load of modern BMW E90 and E91 models with extensive onboard electronics, comfort systems, and advanced diagnostics.

The generator works with the accessory belt drive system, engine control unit, and energy management system, which helps maintain stable voltage across the entire RPM range. This ensures that the starting system, lighting, safety systems, and multimedia operate predictably, without voltage drops or interference.

Benefits of Using an Original BMW Alternator

Using an alternator dedicated to the N57 unit in the E90/E91 series ensures:

• correct fitment to mounting points and the accessory drive system,
• proper interaction with the factory engine control unit and energy management system,
• appropriate charging characteristics for a diesel engine,
• maintenance of operating parameters in line with manufacturer specifications.

This makes an alternator from this series a particularly beneficial choice for workshops and users who expect predictable electrical system behavior after component replacement.

Technical Characteristics and Compatibility

The alternator belongs to the Alternators and Generators group and is structurally prepared to work with diesel engines. Its appropriate current capacity allows it to handle standard equipment as well as additional consumers often found in BMW 3 Series vehicles with richer equipment packages.

The presence of the OEM part number and related interchangeable numbers facilitates unambiguous identification of the component in service catalogs and parts selection systems. This is particularly important when working with the N57 unit, where the compatibility of the alternator's electrical and mechanical parameters directly impacts the durability of the accessory belt, tensioner, and the correct operation of the engine control unit.

Application in N57 Diesel Engines

N57 diesel engines used in BMW E90 and E91 generate high loads for the electrical system, especially during frequent starts, operation in low temperatures, and intensive use of consumers. The 150A alternator is designed to meet these demands, ensuring stable charging even with a large number of active systems.

For users and service centers, this means the ability to restore correct electrical system operation without the need for modifications to wiring harnesses, mounting points, or control unit software – the key is simply selecting the correct OEM part number or reference numbers.

Condition, Verification, and Safe Selection

The offered alternator is a used part, which in workshop practice represents a reasonable compromise between repair cost and maintaining the original manufacturer's specifications. Before installation, a standard check of the charging system, accessory belt condition, and ground connections is recommended to fully utilize the component's capabilities.

For confident selection, it is advisable to use the OEM part number, interchangeable numbers, and engine designations, and if necessary, verify the vehicle configuration by VIN. This approach minimizes the risk of incompatibility and speeds up the service process.

If you are planning a comprehensive repair or upgrade of the charging system area in your BMW and need other parts from the same group, such as alternator housings, pulleys, or mounting brackets, check the available parts in the BMW Alternators and Generators category.

To better prepare for purchasing a used alternator and other components, you can use the practical Global Parts guide – detailed tips on verifying OEM numbers, assessing condition, and safe purchasing practices can be found in the article Safe Online Purchase of Used Car Parts – A Step-by-Step Guide.