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Sierra 18-5966-1 Marine Alternator 55 Amp Single Groove Pulley

Manufacturer

Sierra

<h3>Sierra: Six Decades of Marine Aftermarket Excellence</h3><p><strong>Sierra</strong> has spent nearly 60 years earning its reputation as one of the most trusted names in the marine aftermarket industry. Originally focused on engine and drive components for boats, the brand has grown into a comprehensive source for nearly everything a boater needs to keep their vessel running at its best — from precision instrumentation to complete engine rebuild hardware.</p><p>Now operating as a brand of Dometic, Sierra manages global aftermarket distribution from a 300,000 sq. ft. facility in Litchfield, Illinois. The Sierra brand today encompasses not only its flagship marine parts line but also well-established marine names like Shields and Moeller, offering boaters a broader catalog than ever before. Whether you own an outboard, inboard, or sterndrive, Sierra's engineering team designs products to meet or exceed OEM specifications.</p><h3>Precision Instrumentation You Can Trust on the Water</h3><p>One of Sierra's most recognized product areas is its marine instrumentation lineup. The brand's <a href="/7570-sierra-gauge-set-1480">gauge sets</a> cover everything from classic analog instrument clusters to advanced digital multi-function displays. Sierra offers packages suited to outboards, sterndrives, and gasoline-powered inboards, with options ranging from coordinated analog kits in styles like Arctic, Eclipse, and Amega to modern touchscreen solutions like the R3 multi-function gauge. Features such as scratch-resistant domed glass lenses, silicone-dampened pointers, and perimeter backlighting make these instruments highly readable in all conditions.</p><p>Behind every accurate gauge reading is a properly calibrated sending circuit. Sierra's <a href="/7570-sierra-gauge-resistor-47908">gauge resistors</a> are a critical part of that chain, ensuring the signals from sensors and sending units are correctly interpreted by your instruments. These components are built to marine-grade standards to resist moisture, vibration, and corrosion — the realities of life on the water.</p><h3>Engine Internals Built to OEM Standards</h3><p>Sierra's history in marine power is perhaps best demonstrated by its deep catalog of engine components. The brand's <a href="/7570-sierra-engine-gasket-set-5404">engine gasket sets</a> cover a wide range of outboard and inboard applications and are engineered to deliver reliable seals in the demanding thermal and chemical environment of a marine engine. For boaters performing seasonal overhauls, top-end rebuilds, or full engine restorations, Sierra gasket kits are a go-to resource trusted by professional marine technicians and DIY boaters alike.</p><h3>A Complete Marine Parts Partner</h3><p>Beyond instrumentation and engine internals, Sierra's catalog spans fuel systems, electrical supplies, steering components, shore power, and more — all covered by what the brand calls an industry-leading warranty. Sierra also maintains a comprehensive parts-finder tool that enables cross-referencing with OEM part numbers from major manufacturers including Mercury, Yamaha, Suzuki, Volvo Penta, and others, making it straightforward to find the right replacement part for virtually any application.</p>

Part Number

118-5966-1
09/12/2036 7:17 AM
Sale Price

$239.76

In Stock (7)

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Usually delivered within 2 days

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Product Details

The Sierra 18-5966-1 is a high-quality marine alternator designed for MerCruiser stern drive and inboard engines. This 55-amp, 12-volt alternator features a Mando-style design with a single groove V-belt pulley and 2-inch mounting foot, providing reliable charging performance for marine applications.

Key Features:

  • 55 amp output rating for dependable electrical charging
  • 12-volt system with internal voltage regulator
  • Single groove V-belt pulley configuration
  • Mando-style 2-wire design
  • Meets or exceeds USCG and SAE J1171 safety requirements
  • 100% load-tested for assured reliability
  • Built to OEM specifications for precise fit

This alternator fits 1982 and newer GM 4-cylinder engines, as well as 1982-1996 GM V-6 and V-8 engines (prior to serpentine belt systems). It replaces MerCruiser OEM part numbers 817119A4, 817119A1, 12449A1, 12449, 92497A3, 92497, and 98555A1, as well as Mallory 9-19101. Sierra Marine has over 50 years of experience manufacturing reliable aftermarket parts for the marine industry.

Delivered on time and part was as expected at a fair price. i would buy again from these guys.

Good experience

THANKS

Excellent prices, blazingly, fast shipping and items are exactly as described on the website. You beat any of my local tire shops for the best price for what I was looking for.

Good product and good price

Great so far

Smooth

Great working with.

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