Bosch Alternator 12V 90A Part No. 1986A00783

This Bosch alternator is a 12V, 90A unit supplied as each, with part number 1986A00783 and pin code IR139. It is listed with an internal regulator, CW rotation, and a 6 groove pulley, so those details should be checked carefully against the vehicle before ordering.

Mounting and physical dimensions matter with alternators, and this unit is specified with a twin leg alternator mount, inside mounting legs of 82mm, mount centres A of 163mm, a pivot hole diameter of 10mm, and an adjusting hole diameter of 8mm. The pulley outside diameter is 64mm.

The Bosch listing also notes corrosion resistance, quality raw materials, and a reduction drive designed to maintain continual speeds for easier starting. Those are useful construction and operation details, but fitment still depends on matching the part number and application details to the vehicle already fitted.

Key Features

• Bosch alternator, 12V 90A
• Part number 1986A00783
• Internal regulator
• CW rotation
• 6 groove pulley
• Twin leg alternator mount

Specifications

• Voltage: 12V
• Output: 90A
• Regulator type: internal
• Rotation: CW
• Pulley section: 6 groove
• Pulley outside diameter: 64mm
• Alternator mount: twin leg
• Inside mounting legs: 82mm

Fitment guidance

• Fitment information provided for Audi A4 applications
• Fitment information provided for Volkswagen Passat applications
• Audi A4 references include model years 1995 to 2001 in the supplied application list
• Volkswagen Passat references include model years 1996 to 2005 in the supplied application list

Application and Buying Notes

Before buying, compare the part number 1986A00783, pin code IR139, and the mounting layout against the unit currently fitted to the vehicle. The important physical checkpoints here are the twin leg mount, 82mm inside mounting legs, 163mm mount centres A, 10mm pivot hole diameter, and 8mm adjusting hole diameter.

The 12V, 90A rating is the electrical specification you need to match to the vehicle’s charging system requirements. The pulley details also matter: this alternator uses a 6 groove pulley with a 64mm outside diameter and CW rotation, so belt style and rotation direction should be confirmed before purchase.

This alternator is described as using an internal regulator. If the existing unit is regulated differently, or if the connector style and installation layout do not match, the part may not suit the vehicle even if the Bosch branding appears similar. Always verify the full application against the installed alternator rather than relying on appearance alone.

The provided application list points to Audi A4 and Volkswagen Passat coverage, but that still needs to be checked against the exact year, engine setup, and any changes made during the vehicle’s life. Matching the published application alongside the part number is the safest way to avoid a return or installation delay.

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 1986A00783 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, Inside Mounting Legs 82mm, Pin Code IR139, Power Rating (Amp) 90, Pulley Section 6 Groove, Rotation CW, Alternator Mount Twin Leg, Product Group 1 ROTATING ELECTRICAL.

Additional published details for cross-checking include Part No. 1986A00783, Brand BOSCH, Description Bosch Alternator 12V 90A, Adjusting Hole Diameter 8mm, Mount Centres A 163mm, Pivot Hole Diameter 10mm, Pulley Outside Diameter 64mm, Regulator Type Internal, Voltage 12.

Bosch Alternator 12V 90A. Part number 1986A00783 should be checked first. Listed voltage is 12. Listed output rating is 90. These details form the core reference points used by parts interpreters when confirming the correct replacement.

Mount style is Twin 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 1986A00783, 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 90 should be checked carefully. Incorrect selection can affect installation time, return freight, and equipment availability.

Compatibility note: Confirm compatibility using part number 1986A00783, pin code IR139, the 12V 90A specification, and the listed mounting and pulley details before ordering. Vehicle application should be checked against the alternator already fitted, especially on Audi A4 and Volkswagen Passat applications.

FAQ

What is the voltage and output of this alternator?

It is specified as 12V with a 90A power rating. For this listing, part number 1986A00783 is the main reference point. Listed voltage is 12. Listed output rating is 90. Published fitment references include AUDI A4, AUDI A4 1995, AUDI A4 1996. These details should still be checked against the original unit before ordering.

What is the Bosch part number?

The listed part number is 1986A00783. For this listing, part number 1986A00783 is the main reference point. Listed voltage is 12. Listed output rating is 90. Published fitment references include AUDI A4, AUDI A4 1995, AUDI A4 1996. These details should still be checked against the original unit before ordering.

What regulator type does it use?

It uses an internal regulator. For this listing, part number 1986A00783 is the main reference point. Listed voltage is 12. Listed output rating is 90. Published fitment references include AUDI A4, AUDI A4 1995, AUDI A4 1996. These details should still be checked against the original unit before ordering.

What pulley and rotation details are listed?

The alternator has a 6 groove pulley, a 64mm pulley outside diameter, and CW rotation. For this listing, part number 1986A00783 is the main reference point. Listed voltage is 12. Listed output rating is 90. Published fitment references include AUDI A4, AUDI A4 1995, AUDI A4 1996. These details should still be checked against the original unit before ordering.

What mounting measurements are provided?

The listed mounting details are twin leg alternator mount, 82mm inside mounting legs, 163mm mount centres A, 10mm pivot hole diameter, and 8mm adjusting hole diameter. For this listing, part number 1986A00783 is the main reference point. Listed voltage is 12. Listed output rating is 90. Published fitment references include AUDI A4, AUDI A4 1995, AUDI A4 1996. These details should still be checked against the original unit before ordering.

What vehicles are mentioned in the application list?

The supplied fitment references Audi A4 and Volkswagen Passat applications, with years shown in the list for Audi A4 from 1995 to 2001 and Volkswagen Passat from 1996 to 2005. For this listing, part number 1986A00783 is the main reference point. Listed voltage is 12. Listed output rating is 90. Published fitment references include AUDI A4, AUDI A4 1995, AUDI A4 1996. These details should still be checked against the original unit before ordering.