ARCO Marine Premium Replacement Alternator w/Single Groove Pulley - 12V 70A

The ARCO Marine Premium Replacement Alternator w/Single Groove Pulley – 12V 70A (MPN 20102) is engineered for boaters who demand reliable electrical charging on the water. Whether you're running a weeklong fishing expedition, cruising with family, or powering navigation and safety systems during extended time away from the dock, a failing alternator leaves you stranded. This 70-amp unit is built to deliver consistent, clean power to your marine battery bank, keeping everything from your GPS and fish finder to cabin lighting and bilge pump running without interruption.

Built with a self-exciting internal regulator and negative ground configuration, this premium alternator requires only a single-wire connection for installation—no external regulator needed. The single groove pulley integrates seamlessly with standard marine engine belt systems, while the 2-inch mounting foot fits Mercruiser, BRP-OMC, and compatible inboard engines. Ignition protection screens safeguard internal windings from moisture and corrosion, a critical feature in the salt spray and high-humidity marine environment. The 12-volt, 70-amp output ensures ample charging capacity for modern marine electrical loads without risk of undercharging your battery, even under full accessory load.

Anglers and boaters with Mercruiser or OMC inboard systems will find this alternator a plug-and-play solution when replacing a worn OEM unit. Its compact design (8 x 8 x 9 inches) fits tight engine compartments without modification, and the negative ground system ensures compatibility with existing marine wiring harnesses. Installation takes hours rather than days, getting your boat back on the water quickly. Backed by ARCO Marine's reputation for durability, this replacement alternator is the dependable choice for anyone who spends serious time offshore or on freshwater.