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Alternator for Komatsu D20, D21 & EC170Z - 24V 40A

Alternator for Komatsu D20, D21 & EC170Z - 24V 40A

SKU:400-50008

Regular price £224.70 GBP
Regular price Sale price £224.70 GBP
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Alternator for Komatsu D20, D21 & EC170Z - 24V 40A

Fits Komatsu crawlers, compressors, lift trucks and loaders - 24V, 40 Amp, IR/EF

This 24-volt, 40-amp alternator is a direct replacement for a wide range of Komatsu plant fitted with the Nikko IR/EF unit of this specification, including D20 and D21 crawler dozers, EC170Z compressors, FD-series lift trucks and 515/530/540 loaders. It is built to the original specification, giving the same fit, output and mounting as the alternator it replaces, with no modification required for installation.

It replaces the Komatsu 600-821-6110 and 600-821-6120 units and the Nikko 0-33000 series. The alternator is an internal-regulator, external-fan design with a single-groove solid pulley measuring 95mm across, an M12 x 1.75 threaded main mounting hole and M5 x 0.8 output and lamp terminals. Note that the terminal marked "R" is the lamp/trio connection.

Key Features

  • 24-volt, 40-amp output to factory specification
  • Internal regulator, external fan (IR/EF) design
  • Single-groove solid pulley, 95mm OD
  • M12 x 1.75 threaded mounting hole, as original
  • Replaces Komatsu 600-821-6110 / 600-821-6120 and Nikko 0-33000 series
  • 12-month warranty as standard

Technical Specs

Specification Detail
Voltage 24V
Amperage 40A
Polarity Negative earth
Regulator Internal (IR)
Fan Type External (EF)
Pulley Type Single-groove solid pulley, 95mm OD
Mounting M12 x 1.75 threaded, second ear unthreaded, third hole 14mm
Terminals B+ M5 x 0.8, R (lamp) M5 x 0.8
Manufacturer Nikko
Lester Number 12245, 12250, 12251, 12260

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
Komatsu EC170Z / EC170ZS Compressor (4D105 engine) 1986-1995
Komatsu D20A / D20P / D20S Crawler Dozer Not specified
Komatsu D21 / D21A / D21P / D21S Crawler Dozer Not specified
Komatsu D31 Crawler Dozer Not specified
Komatsu FD250 / FD250E / FD280 / FD400 / FD400E Lift Truck Not specified
Komatsu 515 / 530 / 540 Loader Not specified
Komatsu Excavators, Motor Graders and Generator Sets (same 24V IR/EF unit) Not specified

OEM Part Number Cross Reference

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

Part Number Manufacturer / Brand
600-821-5410, 600-821-5540, 600-821-6110, 600-821-6120, 600-861-2110 Komatsu
0-33000-2870, 0-33000-2871, 0-33000-3071, 0-33000-5280, 0-33000-5850, 0-33000-5860, 0-33000-5870, 0-33000-5880, 0-33000-6511, 0-33000-6580 Nikko
ANK0001, ANK0003, RKD25A04 Arrowhead
12245, 12250, 12251, 12260 Lester

Frequently Asked Questions

Will this alternator fit without any modification?

Yes. This is a direct OEM fit and function replacement using the same mounting, pulley and electrical connections as your original unit, so no modification is needed.

How do I confirm it is right for my machine?

Check the number on your existing alternator against the cross reference table above - Komatsu 600-821-6110 / 600-821-6120 and the Nikko 0-33000 series are the usual originals for this fitment.

What is included?

You receive one new alternator, ready to install using your existing bracket, belt and wiring loom.

How can I tell my old alternator has failed?

Common signs include a battery warning light, dim or flickering lights, a battery that won't hold charge, or a whining or growling noise from the alternator itself.

What voltage and output does this alternator provide?

This unit is rated at 24 volts with a 40 amp output, in an internal-regulator, external-fan (IR/EF) configuration.

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