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Alternator for Yanmar Marine Diesel 1GM 2GM 3GM 3HM 4JH - 12V 35A

Alternator for Yanmar Marine Diesel 1GM 2GM 3GM 3HM 4JH - 12V 35A

SKU:400-44041

Regular price £153.90 GBP
Regular price Sale price £153.90 GBP
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Alternator for Yanmar Marine & Industrial Diesel Engines

1GM, 2GM, 3GM, 3HM, 3JH, 4JH series - 12V 35A IR/EF

This alternator is built to OEM specifications as a direct fit-and-function replacement for the Hitachi LR135-105 unit fitted to Yanmar marine and industrial diesel engines, covering the 1GM, 2GM, 3GM, 3HM, 3JH and 4JH families from the late 1970s through to the early 2000s. It bolts onto the original mounting points with no modification required.

It is a 12-volt, 35-amp unit with an internal regulator (IR) and external fan (EF), turning clockwise on a single-groove (V1) pulley, exactly as the factory unit. It replaces Yanmar 128270-77200 and is the equivalent of Sierra Marine 18-6284 and Arco Marine 84135.

Key Features

  • 12-volt, 35-amp output
  • Internal regulator (IR), external fan (EF)
  • Clockwise (CW) rotation, V1 single-groove pulley
  • Covers Yanmar 1GM to 4JH3 marine and industrial engines
  • Replaces Yanmar 128270-77200 and Hitachi LR135-105
  • 12-month warranty as standard

Technical Specs

Specification Detail
Voltage 12V
Amperage 35A
Rotation Clockwise (CW)
Regulator Internal (IR)
Fan Type External (EF)
Pulley V1 (single groove)
Unit Type Hitachi-type alternator

Vehicle Fitment Guide

Years shown are the overall coverage span for this part. Please confirm against the OEM part number on your original unit before ordering.

Make & Model Years
Yanmar 2QM15 1977-1980
Yanmar 1GM, 1GM10 1980-1984
Yanmar 2GM, 2GMF 1980-1984
Yanmar 3GM, 3HM, 3HMF 1980-1984
Yanmar 3JH2, 3JH3 series 1991-2003
Yanmar 4JH, 4JH2L-HTNE, 4JH3, 4JH3ZA series 1982-2003
Yanmar 4GM, 4TD, 4TM, KM2A All years

OEM Part Number Cross Reference

Aftermarket replacement. OEM part numbers are listed for reference only.

Part Number Manufacturer / Brand
128270-77200 Yanmar
LR135-105 Hitachi
LRA01191 Lucas Electrical
18-6284 Sierra Marine
84135 Arco Marine
12109 Lester
AHI0060, 400-44041 Arrowhead / J&N

Frequently Asked Questions

Will this alternator fit without modification?

Yes, it is a direct OEM-spec replacement matching the original mounting, pulley and output of the Yanmar unit.

Is it suitable for marine use?

It is the standard replacement for the alternator supplied on Yanmar GM, HM, JH and JH2 marine diesels, and cross references to Sierra Marine 18-6284 and Arco Marine 84135.

What's included?

One new alternator unit, ready to fit.

How do I know my old alternator has failed?

Signs include a battery that won't hold charge, a charge warning light, or dimming lights at idle.

Dispatched from the UK · 12-month warranty · Fitment support from our technical team
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Shipping calculated at checkout. Free shipping over £150. Terms apply