{"product_id":"mercury-ext-harness-20-ft-84-8m0101642","title":"Mercury – SmartTow Engine-to-Helm Harness | 20-Foot Connection Cable | 84-8M0101642","description":"\u003cp data-start=\"0\" data-end=\"87\"\u003e\u003cstrong data-start=\"0\" data-end=\"87\"\u003eMercury – SmartTow Engine-to-Helm Harness | 20-Foot Connection Cable | 84-8M0101642\u003c\/strong\u003e\u003c\/p\u003e\n\u003chr data-start=\"89\" data-end=\"92\"\u003e\n\u003cp data-start=\"94\" data-end=\"106\"\u003e\u003cstrong data-start=\"94\" data-end=\"106\"\u003eOverview\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-start=\"108\" data-end=\"585\"\u003eSmartTow and Cruise only work as well as the connection between the engine and the helm, and this harness is the link that makes the whole system communicate. The Mercury 84-8M0101642 Engine-to-Helm Harness provides the clean, reliable pathway needed for SmartTow functions on mechanical-control MerCruiser gas engines. Once installed, the helm kit and engine stay in sync, giving the driver smooth pull-ups, steady speeds, and a towing setup that feels modern and predictable.\u003c\/p\u003e\n\u003chr data-start=\"587\" data-end=\"590\"\u003e\n\u003cp data-start=\"592\" data-end=\"608\"\u003e\u003cstrong data-start=\"592\" data-end=\"608\"\u003eKey Features\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli data-start=\"612\" data-end=\"730\"\u003e\n\u003cstrong data-start=\"612\" data-end=\"645\"\u003eSmartTow Communication Link –\u003c\/strong\u003e Connects the engine to the SmartTow\/Cruise helm kit for full towing functionality.\u003c\/li\u003e\n\u003cli data-start=\"733\" data-end=\"833\"\u003e\n\u003cstrong data-start=\"733\" data-end=\"753\"\u003e20-Foot Length –\u003c\/strong\u003e Provides enough reach for most single-engine runabouts and tow-sport layouts.\u003c\/li\u003e\n\u003cli data-start=\"836\" data-end=\"954\"\u003e\n\u003cstrong data-start=\"836\" data-end=\"873\"\u003eMechanical Engine Compatibility –\u003c\/strong\u003e Designed specifically for mechanical-throttle MerCruiser gas engine platforms.\u003c\/li\u003e\n\u003cli data-start=\"957\" data-end=\"1031\"\u003e\n\u003cstrong data-start=\"957\" data-end=\"983\"\u003eSingle-Engine Design –\u003c\/strong\u003e Engineered for one-engine towing setups only.\u003c\/li\u003e\n\u003cli data-start=\"1034\" data-end=\"1123\"\u003e\n\u003cstrong data-start=\"1034\" data-end=\"1053\"\u003eClean OEM Fit –\u003c\/strong\u003e Uses factory-style connectors for a reliable, plug-in installation.\u003c\/li\u003e\n\u003cli data-start=\"1126\" data-end=\"1230\"\u003e\n\u003cstrong data-start=\"1126\" data-end=\"1154\"\u003eStable Signal Transfer –\u003c\/strong\u003e Ensures smooth data flow between the engine control module and helm unit.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr data-start=\"1232\" data-end=\"1235\"\u003e\n\u003cp data-start=\"1237\" data-end=\"1268\"\u003e\u003cstrong data-start=\"1237\" data-end=\"1268\"\u003eEngine \u0026amp; Boat Compatibility\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli data-start=\"1272\" data-end=\"1323\"\u003eMarine-specific MerCruiser mechanical gas engines\u003c\/li\u003e\n\u003cli data-start=\"1326\" data-end=\"1377\"\u003eSingle-engine tow-sport and runabout applications\u003c\/li\u003e\n\u003cli data-start=\"1380\" data-end=\"1432\"\u003eSystems equipped with SmartTow or Cruise helm kits\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr data-start=\"1434\" data-end=\"1437\"\u003e\n\u003cp data-start=\"1439\" data-end=\"1475\"\u003e\u003cstrong data-start=\"1439\" data-end=\"1475\"\u003ePerformance \u0026amp; Practical Benefits\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-start=\"1477\" data-end=\"1992\"\u003eThis harness delivers the stable communication SmartTow depends on. With a solid connection between the helm and the engine, pull-ups feel consistent, and speed control becomes easier for the driver to hold steady—even in turns or light chop. The 20-foot length offers enough flexibility for straightforward routing, and the factory connectors reduce troubleshooting and wiring guesswork. Once installed, the whole SmartTow system responds more predictably, making towing smoother for both the driver and the rider.\u003c\/p\u003e\n\u003chr data-start=\"1994\" data-end=\"1997\"\u003e\n\u003cp data-start=\"1999\" data-end=\"2014\"\u003e\u003cstrong data-start=\"1999\" data-end=\"2014\"\u003eWhy Buy OEM\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-start=\"2016\" data-end=\"2439\"\u003eSmartTow requires precise communication between the helm kit and the engine’s control module. Mercury’s OEM harness is built to match the exact pin layout, signal behavior, and shielding needed for clean data transfer. Aftermarket harnesses often introduce noise or poor connections, which can create inconsistent towing performance. The OEM version installs easily and maintains reliable communication season after season.\u003c\/p\u003e\n\u003chr data-start=\"2441\" data-end=\"2444\"\u003e\n\u003cp data-start=\"2446\" data-end=\"2453\"\u003e\u003cstrong data-start=\"2446\" data-end=\"2453\"\u003eFAQ\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp data-start=\"2455\" data-end=\"2660\"\u003e\u003cstrong data-start=\"2455\" data-end=\"2500\"\u003eQ1: How do I know if I need this harness?\u003c\/strong\u003e\u003cbr data-start=\"2500\" data-end=\"2503\"\u003eIf you’re adding SmartTow or Cruise to a mechanical-throttle MerCruiser gas engine, this harness is required for the helm kit to communicate with the engine.\u003c\/p\u003e\n\u003cp data-start=\"2662\" data-end=\"2815\"\u003e\u003cstrong data-start=\"2662\" data-end=\"2709\"\u003eQ2: Does the 20-foot length fit most boats?\u003c\/strong\u003e\u003cbr data-start=\"2709\" data-end=\"2712\"\u003eYes. It’s designed to reach cleanly from the transom area to the helm on typical single-engine layouts.\u003c\/p\u003e\n\u003cp data-start=\"2817\" data-end=\"2981\"\u003e\u003cstrong data-start=\"2817\" data-end=\"2876\"\u003eQ3: Will this harness affect normal throttle operation?\u003c\/strong\u003e\u003cbr data-start=\"2876\" data-end=\"2879\"\u003eNo. It only carries SmartTow and Cruise communication—your mechanical throttle feel remains unchanged.\u003c\/p\u003e\n\u003cp data-start=\"2983\" data-end=\"3092\"\u003e\u003cstrong data-start=\"2983\" data-end=\"3033\"\u003eQ4: Can this harness be used for twin engines?\u003c\/strong\u003e\u003cbr data-start=\"3033\" data-end=\"3036\"\u003eNo. It is built strictly for single-engine applications.\u003c\/p\u003e\n\u003cp data-start=\"3094\" data-end=\"3255\"\u003e\u003cstrong data-start=\"3094\" data-end=\"3159\"\u003eQ5: Does the harness need any programming after installation?\u003c\/strong\u003e\u003cbr data-start=\"3159\" data-end=\"3162\"\u003eNo additional programming is required. Once connected, the system communicates automatically.\u003c\/p\u003e","brand":"Mercury","offers":[{"title":"Default Title","offer_id":46936005214499,"sku":"84-8M0101642","price":45.31,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0783\/7410\/9475\/files\/PV511445.jpg?v=1698795733","url":"https:\/\/partsvu.com\/en-ca\/products\/mercury-ext-harness-20-ft-84-8m0101642","provider":"PartsVu","version":"1.0","type":"link"}