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Sierra MP39090 Magneto 3-Position Ignition Starter Switch 12V 15A 6 Terminal

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

MP39090
09/11/2036 1:33 AM
Sale Price

$41.86

2 left at this price

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Usually delivered within 2 days

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Fitment guaranteed

Fitment guaranteed

Product Details

The Sierra MP39090 is a heavy-duty 3-position ignition starter switch designed for marine applications. This robust switch features a durable polyester housing that provides maximum corrosion protection in harsh saltwater and freshwater environments, while eliminating the risk of electrical shorts.

Key Features:

  • 3-position operation: Off - Ignition - Start with secure locking mechanism
  • 6 screw terminals for reliable electrical connections
  • 12V system compatible with 15 amp rating
  • 30 amp solenoid capacity for reliable engine starting
  • Polyester construction with inner seal between cylinder for weather resistance
  • 1 1/8" panel cutout required for installation
  • 7/8" mounting hole diameter

This magneto-style ignition switch provides reliable starting control for boats, marine engines, and other 12-volt applications. The sealed construction and corrosion-resistant materials ensure long-lasting performance even in the most demanding marine environments. The lock feature provides security when the vessel is unattended.

Products specifications

Diameter

7/8" Mounting Hole

Type

Switches

Warranty Details

One Year

great

love how it connected to Amazon. Super easy !

So far, excellent lowest price online, will wait for item when shipped.

Best prices I could find online. Thank you

Fast shipping great service!

This is my first time ordering from them, but it certainly will not be my last. They have all the parts I need and the process and ship fast. Great company. And they're prices are awesome.

Best price that i could find anywhere, shipped very quick with no problems.

Hoping for the best looks like good reviews on this waterpump

Best price

No hassle ordering and fast quality shipping at a reasonable price

So far so good

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