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Sierra 18-99401 Johnson/Evinrude Engine Adapter Harness 18-Inch 423-6344

Manufacturer

Sierra

<p>For nearly six decades, Sierra has established itself as one of the marine industry's most trusted names in aftermarket engine and drive parts. Founded as a specialized marine parts manufacturer, Sierra has grown into a comprehensive supplier of replacement components, instrumentation, and accessories for both recreational and commercial boating applications. Operating from their 300,000-square-foot distribution center in Litchfield, Illinois, Sierra serves boat owners and marine technicians worldwide with an extensive catalog of parts engineered specifically for the harsh saltwater environment.</p><h3>Marine Engine Excellence</h3><p>Sierra's reputation was built on delivering precision-engineered internal engine components and drive system parts that meet or exceed OEM specifications. Their <a href="/7570-sierra-engine-gasket-set-5404">engine gasket sets</a> provide critical sealing solutions for inboard and outboard motors, while their <a href="/7570-sierra-engine-complete-assembly-15341">engine complete assemblies</a> offer comprehensive replacement options for major overhauls. Each component undergoes rigorous testing to ensure reliability in demanding marine conditions, from corrosion resistance to temperature cycling performance.</p><h3>Instrumentation and Monitoring Systems</h3><p>Accurate instrumentation is essential for boat operators to monitor engine health and prevent costly breakdowns on the water. Sierra's comprehensive line of <a href="/7570-sierra-gauges-200483">gauges</a> includes everything from fuel pressure and temperature indicators to voltmeters and trim gauges, all designed with marine-grade materials that withstand vibration, moisture, and UV exposure. Their <a href="/7570-sierra-tachometer-gauge-1488">tachometer gauges</a> deliver precise RPM readings critical for optimizing engine performance and fuel efficiency. Supporting these instruments, Sierra's <a href="/7570-sierra-gauge-resistor-47908">gauge resistors</a> ensure proper signal conditioning and accurate readings across various sensor types and engine configurations.</p><h3>Expanded Product Portfolio</h3><p>In 2022, Sierra significantly broadened its scope beyond traditional marine engine parts to encompass a wider range of boating accessories and even outdoor power equipment components. This strategic expansion brought established marine brands like Shields and Moeller under the Sierra umbrella, creating a one-stop resource for marine maintenance and replacement parts. The company now offers fuel systems, electrical components, battery charging solutions, and NMEA electronics alongside their traditional engine parts lineup.</p><h3>Quality Backed by Industry-Leading Warranties</h3><p>What sets Sierra apart in the crowded aftermarket marine parts market is their commitment to standing behind every component they manufacture. Their warranty coverage extends beyond simple part replacement—it includes shop labor, haul-out fees, towing charges, and related incidental costs should a warrantied part fail. This comprehensive protection reflects the company's confidence in their manufacturing processes and quality control standards. For boat owners facing repairs far from shore or mechanics working on customer vessels, this peace of mind is invaluable. Whether you're maintaining an outboard motor, rebuilding an inboard engine, or upgrading your boat's instrumentation, Sierra's decades of marine industry experience and commitment to quality make them a reliable choice for keeping your vessel running at peak performance.</p>

Part Number

18-99401
08/05/2036 6:38 PM
Sale Price

$170.71

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Usually delivered within 2 days

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Product Details

The Sierra 18-99401 (formerly CDI Electronics 423-6344) is an 18-inch engine-end adapter harness designed to interface 1969–1995 Johnson and Evinrude outboard motors with 1996 and newer Deutsch modular control systems. This is the engine-side connector only — a separate boat-side harness is required and sold separately.

Key Features:

  • Adapts 1995 and older Johnson/Evinrude (J/E) outboard engines to 1996 and newer Deutsch-style controllers
  • 18 inches in length — engine-end connector only
  • Compatible with 1969–1972 motors (yellow plug boat-side harness) and 1973–1995 motors (red plug boat-side harness)
  • Replaces OEM part number 0176344 / 176344
  • Formerly sold as CDI Electronics 423-6344 (now consolidated under Sierra Marine)

Installation Notes:

  • For 1969–1972 motors: main plug connects to motor; blue trim plug must be removed and wires directly connected to engine trim wires
  • For 1973–1995 motors: main plug connects to motor; blue trim plug connects to engine trim plug
  • At the controller, three plugs on the new boat-side harness attach to the main control plug, alarm plug, and trim plug
  • Existing boat-side harness must be removed and replaced with OEM 176333 (5 ft), 176334 (10 ft), or 176335 (20 ft)

Cross-Reference Part Numbers:

  • OEM: 0176344 / 176344
  • CDI Electronics: 423-6344
  • Sierra Marine: 18-99401

Great! Shipped really fast as well

Everything was smooth and easy

All good!!!

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Very easy.

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Great price

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