{"product_id":"sierra-18-99454-wiring-harness-for-mercury-mariner-outboard-electrical-systems","title":"Sierra Wire Harness 18-99454 for Mercury and Mariner Outboard Engines","description":"\u003cp\u003eThe Sierra 18-99454 is a wire harness engineered for Mercury and Mariner outboard engine electrical systems. It is built to carry and organize the engine's wiring runs, providing a reliable electrical connection point between engine-mounted components and the boat's control and power systems. A wire harness like this one protects individual wires from vibration, moisture, and abrasion by bundling them into a single, secured assembly, which reduces the chance of chafing, shorts, or connector failure that loose or unprotected wiring can develop over time on a boat engine.\u003c\/p\u003e\u003cp\u003eThis harness is sold as a direct-fit replacement component for the Mercury Outboard electrical system, making it a straightforward swap for a harness that has become brittle, corroded, or damaged. Because it is purpose-built for Mercury and Mariner outboard applications, it is designed to match the factory routing and connection points these engines use, simplifying installation compared to a universal or spliced-in alternative.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Sierra\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 18-99454\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Name:\u003c\/strong\u003e Mercury Mariner Harness\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCategory:\u003c\/strong\u003e Mercury Outboard Electrical System\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.6 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 808282396350\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat engines is the Sierra 18-99454 wire harness designed for?\u003c\/strong\u003e This harness is built for Mercury and Mariner outboard engine electrical systems, part number 18-99454.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the 18-99454 harness weigh?\u003c\/strong\u003e It weighs 0.6 pounds, which is the weight of the Sierra Mercury Mariner Harness as shipped.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs the 18-99454 an OEM or aftermarket part?\u003c\/strong\u003e It is a Sierra-branded replacement harness, sold under Sierra's own part number 18-99454 for the Mercury Outboard electrical system.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat does a wire harness like the 18-99454 do on an outboard engine?\u003c\/strong\u003e It bundles and protects the engine's electrical wiring runs, keeping connections organized and shielded from vibration, moisture, and abrasion in the Mercury Outboard electrical system.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes the Sierra 18-99454 fit Mariner-branded outboards as well as Mercury?\u003c\/strong\u003e Yes, the 18-99454 is identified as a Mercury Mariner Harness, meaning it is designed for both Mercury and Mariner outboard engines.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the UPC for the Sierra 18-99454 harness?\u003c\/strong\u003e The UPC for this Mercury Mariner Harness is 808282396350.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan the 18-99454 harness replace a damaged or corroded factory harness?\u003c\/strong\u003e Yes, it is intended as a replacement wire harness for the Mercury Outboard electrical system when the original wiring has failed or corroded.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs any installation hardware included with the 18-99454?\u003c\/strong\u003e The listing for this Sierra part covers the wire harness itself; no additional included hardware is specified.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat category of part is the 18-99454?\u003c\/strong\u003e It is classified within the Mercury Outboard Electrical System category as a wire harness.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhy choose a purpose-built harness over a universal replacement?\u003c\/strong\u003e The Sierra 18-99454 is made specifically for the Mercury and Mariner outboard electrical system, so its routing and connections are designed to match the application rather than requiring splicing or modification.\u003c\/p\u003e","brand":"Sierra","offers":[{"title":"Default Title","offer_id":48988444786907,"sku":"SIE-18-99454","price":117.77,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/CDI-414-0043_lg__92320.1722500287.500.750.jpg?v=1785329193","url":"https:\/\/www.goodvibesmarina.com\/products\/sierra-18-99454-wiring-harness-for-mercury-mariner-outboard-electrical-systems","provider":"Good Vibes Marina","version":"1.0","type":"link"}