Skip to product information
1 of 7

Alternator for Mercruiser, OMC, Volvo Penta & Pleasurecraft Marine - 12V 55A

Alternator for Mercruiser, OMC, Volvo Penta & Pleasurecraft Marine - 12V 55A

SKU:400-46024

Regular price £201.00 GBP
Regular price Sale price £201.00 GBP
Sale Sold out
Taxes included. Shipping calculated at checkout.

Free shipping over £150. Terms apply

Alternator for Mercruiser, OMC, Volvo Penta & Pleasurecraft Marine - 12V 55A

Mando-style inboard marine unit · Lester 12174 / 12177 · Arrowhead AMN0010

This alternator is built to OEM specifications as a direct fit and function replacement for Mando-style inboard and sterndrive marine engines from Mercruiser, OMC, Volvo Penta and Pleasurecraft. It is an IR/EF unit - internally regulated with an external fan - rated at 12 volts and 55 amps.

The unit rotates counter-clockwise (CCW) and uses a six-groove (S6) pulley, matching the original factory configuration for a straight bolt-in fit.

Key Features

  • 12-volt, 55-amp output
  • IR/EF design - internally regulated, externally cooled
  • Counter-clockwise (CCW) rotation
  • S6 (6-groove) pulley
  • Mando-style inboard marine replacement
  • 12-month warranty as standard

Technical Specs

Specification Detail
Voltage 12V
Amperage 55 Amp
Rotation CCW (Counter-Clockwise)
Regulator IR (Internally Regulated)
Fan Type EF (External Fan)
Pulley Type S6 (6-Groove)

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
Mercruiser sterndrive & inboard engines Not specified - confirm against OEM part number
OMC marine engines Not specified - confirm against OEM part number
Volvo Penta marine engines Not specified - confirm against OEM part number
Pleasurecraft marine engines Not specified - confirm against OEM part number

OEM Part Number Cross Reference

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

Part Number Manufacturer / Brand
AC155616 Mando
3857813, 3860769 Volvo Penta
AMN0010 Arrowhead
12174, 12177 Lester

Frequently Asked Questions

Will this alternator fit my marine engine without modification?

Yes. This is a direct OEM-fit replacement built to the same specification (12V, 55A, IR/EF, CCW rotation, S6 pulley) as the original Mando-style unit, so no modification is required.

How do I confirm this is the right unit for my engine?

Compare the number stamped on your existing alternator against the cross reference table above - Mando AC155616, Volvo Penta 3857813 or 3860769, Arrowhead AMN0010, or Lester 12174 / 12177 all indicate this unit.

What's included with this part?

You receive the alternator unit only. Mounting hardware and pulleys are not included unless already fitted to the original unit you are replacing.

How can I tell my old alternator has failed?

Common signs include a warning light staying on, dimming battery-charging performance, a dead or slowly draining battery, or unusual whining noises from the unit.

Why does rotation direction matter?

This unit rotates counter-clockwise (CCW). Fitting an alternator with the wrong rotation direction will not charge correctly, so always confirm your original unit's rotation before ordering.

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