Bosch Alternator 12V 140A 1986A00902

This Bosch alternator is a 12V, 140A unit supplied under part number 1986A00902. It is listed as an alternator type excluding vacuum pump, with an internal regulator, a 6 groove pulley section, and a quad leg alternator mount.

The application note supplied with the part states it is to suit Audi A3 with AXW engine. The fitment data also references selected Audi and Volkswagen applications, but the safest way to confirm suitability is to match the part number, mounting style, pulley details, and electrical specification against the vehicle being serviced.

Key physical and electrical details include a pulley outside diameter of 56mm, inside mounting legs of 60mm, mount centre to centre of 127mm, and a double pivot lever fastening type. These dimensions matter when checking alignment and installation space on the vehicle.

Bosch lists this alternator with a 12 month warranty, manufactured in China, and packaged as one each. For workshop and retail buyers alike, the practical value is in matching the 12V system, 140A charge current, and the exact mounting pattern before ordering.

Key Features

• 12V alternator with 140A charge current
• Bosch part number 1986A00902
• Internal regulator
• Quad leg alternator mount
• 6 groove pulley section
• Alternator type: excl. vacuum pump

Specifications

• Brand: Bosch
• Product type: Alternator
• Voltage: 12V
• Charge current / power rating: 140A
• Part No.: 1986A00902
• Pin code: IR139
• Pulley outside diameter: 56mm
• Pulley section: 6 groove

Fitment guidance

• Supplied application note: Audi A3 with AXW engine
• Fitment data also references selected Audi and Volkswagen applications
• Do not rely on make alone; confirm the exact engine code, mounting pattern, pulley arrangement, and part number before purchase

Application and Buying Notes

The most important check on this alternator is the part number 1986A00902, followed by the electrical rating of 12V and 140A. If the vehicle uses a different output, pulley arrangement, or mounting pattern, the alternator may not be suitable even if the vehicle badge looks similar.

The mounting details are specific: quad leg mount, 60mm inside mounting legs, 127mm mount centre to centre, and double pivot lever fastening. These dimensions are what help determine whether the alternator physically sits and aligns correctly in the engine bay.

The pulley specification is also important. This unit has a 56mm outside diameter pulley and a 6 groove section, and the listing notes it is an alternator excluding vacuum pump. Those details need to match the existing unit and belt drive setup.

A V-belt / V-ribbed belt is listed as a recommended additional repair. In practice, it is sensible to inspect the belt condition at the same time as the alternator, because belt wear, misalignment, or contamination can affect charging performance and shorten the life of the replacement unit.

The application note names Audi A3 with AXW engine, while the fitment data also points to selected Audi and Volkswagen applications. That is useful context, but final confirmation should still be made against the vehicle identification, current alternator, and the measured mounting and pulley details.

Before supply, the safest approach is to confirm the original unit details against the listed part number, voltage, output rating, mounting arrangement, and pulley configuration. That checking process is standard practice in the parts trade because visually similar units can still differ in service-critical ways.

For workshop, fleet, and equipment applications, accurate identification of part number 1986A00902 helps avoid unnecessary freight, additional labour, and vehicle or machine downtime. Where the application is not straightforward, the original unit, OEM reference, or workshop records should be used as the primary confirmation point.

Relevant published details for this unit include Type ALTERNATOR, Unit of Measure EACH, Warranty 12 Months, Pin Code IR139, Pulley Outside Diameter 56mm, Regulator Type Internal, Alternator Mount Quad Leg, Alternator Charge Current [A] 140, Alternator Type excl. vacuum pump, Packaging length 23.9.

Additional published details for cross-checking include Packaging height 20, Product Group 2 ALTERNATORS, Part No. 1986A00902, Brand BOSCH, Description Bosch Alternator 12V 140A, Inside Mounting Legs 60mm, Power Rating (Amp) 140, Pulley Section 6 Groove, Voltage 12.

Bosch Alternator 12V 140A. Part number 1986A00902 should be checked first. Listed voltage is 12. Listed output rating is 140. These details form the core reference points used by parts interpreters when confirming the correct replacement.

Mount style is Quad Leg. Regulator type is Internal. Pulley configuration is 6 Groove. Those physical and electrical details should line up with the original unit before the replacement is approved for fitment.

For part number 1986A00902, the normal identification sequence is part number, electrical rating, mounting arrangement, connector or terminal style, and pulley or drive details. Using those checkpoints helps confirm that the listed unit matches the service requirement rather than only looking similar.

For a alternator in workshop, fleet, trade, agricultural, or construction service, the listed voltage 12 and output 140 should be checked carefully. Incorrect selection can affect installation time, return freight, and equipment availability.

Compatibility note: Confirm fitment using Bosch part number 1986A00902, the 12V 140A specification, and the mounting and pulley details before ordering. If any of the vehicle, engine code, or bracket dimensions differ, check the existing alternator against the listed measurements first.

FAQ

What vehicle is this alternator listed to suit?

The supplied application note states Audi A3 with AXW engine. The fitment data also references selected Audi and Volkswagen applications, but the exact vehicle should still be confirmed by part number, engine code, and mounting details.

What is the part number?

The Bosch part number supplied is 1986A00902.

What electrical rating does it have?

It is a 12V alternator with a 140A charge current, also listed as 140 amp power rating.

Does it have an internal regulator?

Yes. The regulator type is listed as internal.

What pulley and mount details should be checked?

The alternator has a 56mm pulley outside diameter, a 6 groove pulley section, a quad leg mount, 60mm inside mounting legs, and 127mm mount centre to centre.

Is any extra repair item suggested?

Yes. A V-belt or V-ribbed belt is listed as a recommended additional repair, so the belt condition should be checked during replacement.