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Alternator for Mercury Outboard 115-200 HP 1999-2014

Alternator for Mercury Outboard 115-200 HP 1999-2014

SKU:400-12306

Regular price £220.00 GBP
Regular price Sale price £220.00 GBP
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Alternator for Mercury Outboard Engines

115-200 HP · 1999-2014 · Delco 5SI Type

This aftermarket alternator is built on the compact Delco 5SI platform (smaller diameter than the 7SI) engineered for Mercury Marine 2.5L outboard powerheads, with a 4-groove pulley, B+ terminal at the 1 o'clock position and plug connector at 12 o'clock on the rear cover.

High-temperature epoxy and grease, heavy-duty rectifiers and a quality internal regulator give a direct-fit OEM replacement for the Mercury Marine 857006T, 875285T1, 881248T and 889955 alternators, supplied with final test results and a performance curve.

Key Features

  • 50 Amp output, 12 Volt, internally regulated
  • Delco 5SI type, compact diameter, 4-groove pulley
  • B+ terminal at 1:00, plug at 12:00 (rear cover)
  • Same regulator pin connection as the Delco 7SI family
  • High-temperature epoxy & grease for marine engine bays

Technical Specs

Specification Detail
Voltage 12V
Amperage 50A
Regulator Internal (IR)
Pulley 4-Groove
Alternator Family Delco 5SI
Weight 10.00 lbs

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
Mercury 115CXL / 115L / 115XL Optimax 1999-2014
Mercury 135CXL / 135L / 135XL Optimax 1999-2014
Mercury 150 / 175 series 1999-2014
Mercury 200CXL / 200L / 200XL 1999-2014
MerCruiser 575SCI 2000

OEM Part Number Cross Reference

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

Part Number Manufacturer / Brand
857006T, 875285T1, 881248T, 889955, 889955A03 Mercury Marine
19020703, 19020706 Delco
20840 Arco Marine
8470 Lester
18-6454 Sierra Marine
1-2487-01DR WAI

Frequently Asked Questions

Will this alternator fit my outboard without modification?

Yes, it is a direct, bolt-on replacement using the same pulley, mounting and terminal layout as the original Mercury Marine alternator.

What is included?

One complete 50A, 12V outboard alternator, ready to fit.

How can I tell my existing alternator has failed?

Look out for a dashboard charge warning light, a battery that will not hold charge, or dimming/flickering electrical accessories while running.

How do I tell this apart from the larger Delco 7SI alternator?

This 5SI unit has a smaller body diameter than the 7SI, though it shares the same regulator pin connection layout.

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