{"product_id":"aa-ignition-marine-ignition-coil-for-mercruiser-gm-v6-v8-thunderbolt-iv-v-direct-fit-sealed","title":"AA Ignition Marine Ignition Coil for MerCruiser GM V6\/V8 Thunderbolt IV\/V Direct-Fit, Sealed","description":"\u003cstrong\u003eAA Ignition's marine ignition coil is a direct-fit replacement for select MerCruiser engines, restoring high-voltage spark for reliable starting and smoother running.\u003c\/strong\u003e\n\nThis coil is designed specifically for inboard marine engines using the Thunderbolt IV \u0026amp; V ignition systems and fits a range of GM V6 and V8 MerCruiser applications. Built with marine-grade materials and sealed against moisture, heat, and vibration, it replaces common OEM numbers such as 18-5438, 392-805570A2, 392-7803A4, 392-805570A1, 72115, and 40511. The unit installs without modification and is backed by a two-year warranty from AA Ignition.\n\n\u003ch3\u003eWill this coil fit my MerCruiser engine?\u003c\/h3\u003e\n\u003cp\u003eConfirm fit by matching any of the listed part numbers on your original coil or by verifying your engine uses the Thunderbolt IV or V ignition system. This coil is engineered as a direct replacement for MerCruiser GM V6 and GM V8 308 and 350 engines that use those ignition systems.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eReplaces OEM numbers: 18-5438, 392-805570A2, 392-7803A4, 392-805570A1, 72115, 40511\u003c\/li\u003e\n  \u003cli\u003eCompatible with MerCruiser GM V6 and V8 308\/350 with Thunderbolt IV \u0026amp; V\u003c\/li\u003e\n  \u003cli\u003eCheck stamping on original coil or consult engine service manual for confirmation\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow does this coil improve engine performance on the water?\u003c\/h3\u003e\n\u003cp\u003eA healthy ignition coil delivers the high-voltage pulse needed for consistent spark at the plugs, which helps reduce hard starting, misfires, and rough idling. Replacing a worn coil returns reliable combustion timing and smoother throttle response, especially under load or in choppy conditions.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eRestores strong spark to eliminate no-start and intermittent misfire issues\u003c\/li\u003e\n  \u003cli\u003eImproves throttle response and smoother idle when paired with good plugs\u003c\/li\u003e\n  \u003cli\u003eSealed construction resists marine moisture and vibration for stable performance\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow straightforward is the installation?\u003c\/h3\u003e\n\u003cp\u003eInstallation is plug-and-play for compatible engines—no cutting, splicing, or custom brackets required. The coil matches factory mounting points and electrical connections used by the Thunderbolt systems, making it suitable for DIY replacement or quick shop service.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eDirect-fit replacement—uses original mounting and connectors\u003c\/li\u003e\n  \u003cli\u003eRecommended to inspect\/replace spark plugs and distributor cap at same time\u003c\/li\u003e\n  \u003cli\u003eTwo-year warranty provides added confidence after installation\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat quality and warranty can I expect?\u003c\/h3\u003e\n\u003cp\u003eThis unit is not OEM-branded but is manufactured to meet or exceed factory specifications with marine-grade sealing and finishes. AA Ignition covers the coil with a two-year warranty to protect against manufacturing defects and premature failure.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eMarine-grade materials and sealed against heat, moisture, and vibration\u003c\/li\u003e\n  \u003cli\u003eEngineered to match OEM electrical output and fitment requirements\u003c\/li\u003e\n  \u003cli\u003e2-year warranty handled through AA Ignition for replacements\u003c\/li\u003e\n\u003c\/ul\u003e\n\nWho this is for: If you own a MerCruiser-powered boat that uses the Thunderbolt IV or V ignition system and youre experiencing hard starts, intermittent misfires, weak spark, or rough running, this AA Ignition coil is a cost-effective direct replacement option. It's also suitable for owners who prefer a sealed, marine-grade aftermarket coil that installs quickly and is backed by a two-year warranty. Technically inclined boaters and marine technicians will appreciate the straightforward fitment and OEM-compatible specifications, while owners preparing seasonal maintenance can use this coil as part of a tune-up alongside new spark plugs and ignition components.\n\u003csection class=\"product-faq-snippet\"\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Does this coil fit MerCruiser Thunderbolt IV and V?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes. Its a direct replacement for MerCruiser GM V6 and V8 (308\/350) engines using Thunderbolt IV and V when part numbers match.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: What warranty does AA Ignition offer?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: AA Ignition provides a two-year warranty covering defects and premature failure; contact support for replacement assistance.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"AA Ignition","offers":[{"title":"Default Title","offer_id":48086291480734,"sku":"B07GL4TM27","price":46.23,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0781\/2041\/9486\/files\/aa-ignition-coil-front-view.jpg?v=1785893915","url":"https:\/\/northtrailauto.ca\/products\/aa-ignition-marine-ignition-coil-for-mercruiser-gm-v6-v8-thunderbolt-iv-v-direct-fit-sealed","provider":"North Trail Auto","version":"1.0","type":"link"}