Bosch Alternator Voltage Regulator 12V - 1 986 AE0 081

Product Details & Application

This Bosch alternator voltage regulator (1 986 AE0 081) is a 12 V replacement regulator used across a wide range of BMW and Mercedes-Benz alternator applications. It regulates alternator output voltage to protect the battery and vehicle electrical system during charging. Identification for this part is primarily by OEM reference cross-reference - match at least one supplied OE number to the regulator or alternator being replaced before ordering.

Key Details

SKU

1986AE0081

Component

Alternator Voltage Regulator

Brand

Bosch

Part MPN

1 986 AE0 081

Key Benefits

• Genuine Bosch replacement regulator.
• Extensive BMW and Bosch OEM cross-references supplied for pre-order verification.
• Compact 12 V unit, 90 x 43.5 x 120 mm.

OEM Reference Numbers

• Bosch: 1 986 AE0 081
• F 00M A45 221
• F 00M 145 880
• F 00M 145 262
• F 00M 145 285
• F 00M 145 312
• F 00M 145 655
• 0 124 515 051
• 0 124 515 098
• 0 124 525 042
• 0 124 525 045
• 0 124 525 048
• 0 124 525 059
• 0 124 525 561
• 0 399 604 014
• 0 399 604 028
• BMW: 12 31 7 523 059
• 12 31 7 540 656
• 12 31 7 505 922

Product Specifications

Application & Compatibility

• Fits a range of BMW and Mercedes-Benz alternator applications that use Bosch alternators cross-referencing the listed OE numbers.
• Identification for this part is by OEM cross-reference - match the regulator or host alternator's OE number against the list above before ordering.
• Confirm 12 V system voltage, physical dimensions, and terminal/connector orientation on the removed unit before fitting.

Installation / Use / Maintenance Tips

• Disconnect the battery before removing or installing the regulator.
• Inspect the slip rings and brush contact surfaces on the alternator before fitting the new regulator - worn slip rings will prematurely wear a new regulator.
• Ensure the regulator and main B+ terminal connections are clean and secure.
• After installation, verify charging voltage at idle and under load, and confirm no battery or charging warnings remain.

Common Questions

How do I confirm this is the right alternator voltage regulator?
Match one of the listed OEM reference numbers (Bosch or BMW) on the removed regulator or on the alternator itself to one of the cross-references above. Confirm the physical size and terminal layout before ordering.

What OEM part numbers does this cross-reference?
Cross-reference numbers are listed in the OEM Reference Numbers section above. Match at least one to your original part before ordering.

What brand is this part?
This listing is for Bosch alternator voltage regulator.