ARCO 12V 55A Inboard Alternator, Single Groove Pulley

Description

The ARCO Premium Replacement Inboard Alternator is a 12V, 55A marine charging unit designed for OMC Cobra, Prestolite/Motorola, and related Volvo Penta applications. It uses a 2-inch mounting foot, negative-ground electrical configuration, internal voltage regulation, and an included single-groove pulley, giving installers the core components needed for a direct-style replacement.

ARCO engineers its alternators for marine reliability and precise fitment rather than treating them as generic automotive substitutions. Each alternator is manufactured with a focus on performance and quality and must meet or exceed OEM performance requirements before it is boxed.

The broad cross-reference list includes BRP/OMC 983424, 984565, 985465, 985466, 986008, 988247, 3853853, 3854182, 3854809, 3857298, and 3860769. Volvo references include 3850927-9, 3853853-4, 3854182-7, 3854809-5, 3857298, 3860173, and 857298. Sierra references include 18-6260 and 18-6842. Matching one of these references or confirming the original alternator dimensions helps verify compatibility before installation.

When properly installed, ARCO covers the alternator against defects in materials and workmanship for 12 months in leisure use and 90 days in commercial or racing applications. Eligible rotating-electric products can receive an additional year of coverage when registered within 30 days. There is more in our marine alternators.