Bosch Alternator 12V 135A Part No. 1986A01125

This Bosch alternator is a 12V unit with a 135A power rating, supplied as part number 1986A01125. It is listed as an alternator in the rotating electrical category and uses an internal regulator, so it suits applications designed around a 12V charging system and this style of regulator arrangement.

Key mounting details are provided for reference, including a twin leg alternator mount, 100mm inside mounting legs, 198mm mount centre to centre, a 13mm pivot hole diameter and a 1/2 UNC adjusting hole diameter. The shaft diameter is 22mm, which is another important check point when comparing against the original unit.

This alternator is manufactured in Spain and weighs 7.8kg. It is described as corrosion resistant and made from high quality raw materials, with a reduction drive intended to maintain continual speeds for easier starting. Those details are useful, but fitment should still be confirmed against the vehicle or machine application before ordering.

The unit is sold each and carries a 12 month warranty. As with any charging component, the safest approach is to compare the part number, voltage, mounting layout and hole dimensions before fitting, especially where the original alternator has been repaired, replaced or modified previously.

Key Features

• 12V alternator with 135A output
• Bosch part number 1986A01125
• Internal regulator type
• Twin leg alternator mount
• Made in Spain
• Corrosion resistant construction

Specifications

• Voltage: 12V
• Power rating: 135A
• Part No.: 1986A01125
• Regulator type: Internal
• Alternator mount: Twin leg
• Inside mounting legs: 100mm
• Mount centre to centre: 198mm
• Pivot hole diameter: 13mm

Fitment guidance

• Use the Bosch part number 1986A01125 as the main reference when checking fitment.
• Confirm the vehicle or machine is set up for a 12V, 135A alternator with an internal regulator.
• Check the twin leg mount arrangement, 100mm inside mounting legs and 198mm mount centre to centre before ordering.
• Compare the 13mm pivot hole and 1/2 UNC adjusting hole against the existing alternator.
• Confirm the 22mm shaft diameter matches the original unit.
• Known application families listed include Atkinson, Case, Case IH, Cummins, Dynapac, International, John Deere and New Holland, but the exact model and year still need to be checked against the vehicle.

Application and Buying Notes

For charging-system work, the most important checks on this Bosch unit are the 12V system voltage, 135A output, internal regulator type and the mounting dimensions. If any of these differ from the original alternator, the part may not suit the application without further verification. The listed twin leg mount and 198mm centre-to-centre spacing are especially important on equipment where brackets have not been changed.

The part number 1986A01125 is the clearest identifier to compare against the old alternator, invoice record or parts catalogue. Where the original unit is missing, the mounting layout, shaft diameter and hole sizes become the next most useful checks. The 22mm shaft diameter, 13mm pivot hole and 1/2 UNC adjusting hole are practical details that can quickly confirm whether the alternator will physically match the installation.

This alternator is listed at 7.8kg and is manufactured in Spain. Those details can help when comparing replacement parts of similar appearance, but they do not replace a fitment check. If the machine uses a different regulator type, different bracket spacing or a different pulley and shaft arrangement, the correct replacement may be another Bosch variant rather than this exact unit.

The fitment references supplied include a range of Atkinson, Case, Case IH, Cummins, Dynapac, International, John Deere and New Holland applications. That is a useful guide, but the safest buying decision is still to match the exact application, model and year where available, then confirm the alternator specifications against the original part before fitting.

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 1986A01125 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 100mm, Power Rating (Amp) 135, Shaft Diameter 22mm, Alternator Mount Twin Leg, Packaging length 28, Packaging height 22.5, Weight 7.8kg.

Additional published details for cross-checking include Product Group 1 ROTATING ELECTRICAL, Part No. 1986A01125, Brand BOSCH, Description Bosch Alternator 12V 135A, Adjusting Hole Diameter 1/2 UNC, Pivot Hole Diameter 13, Regulator Type Internal, Voltage 12, Mount Cnt to Cnt 198mm, Packaging width 22.5.

Bosch Alternator 12V 135A. Part number 1986A01125 should be checked first. Listed voltage is 12. Listed output rating is 135. 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. Those physical and electrical details should line up with the original unit before the replacement is approved for fitment.

Compatibility note: Please confirm fitment using Bosch part number 1986A01125, the 12V 135A specification and the listed mounting dimensions before ordering. Application references are provided as a guide only and should be checked against the exact vehicle or machine model.

FAQ

What is the part number for this Bosch alternator?

The part number listed is 1986A01125.

Is this alternator 12V or 24V?

It is a 12V alternator.

What is the output rating?

The alternator is rated at 135A.

Does it have an internal or external regulator?

It uses an internal regulator.

What mounting details are listed?

The listed mounting details include a twin leg alternator mount, 100mm inside mounting legs, 198mm mount centre to centre, a 13mm pivot hole diameter and a 1/2 UNC adjusting hole diameter.

What should I check before buying?

Check the Bosch part number 1986A01125, the 12V and 135A specification, the internal regulator type and the mounting and shaft dimensions against the original alternator.