Replacement Alternator for Mercruiser MODEL 4.3L Stern Drive - 12 Volts 55 Amps

Replacement for the Mercruiser MODEL 4.3L Stern Drive, this 12 volt 55 amp marine alternator restores dependable charging to the engine electrical system. Engineered as a direct-fit service part, it follows the original Mando-style design used in this application, supplying steady output to keep starting batteries charged and onboard accessories powered. It is supplied complete and ready to install in place of the original unit, making it a practical choice for routine service work, seasonal preparation, or repair after a charging system failure.

Key Features & Benefits

• Delivers 12 volts at 55 amps to match the original charging capacity of the engine
• Internal voltage regulator maintains consistent output across the full range of engine speeds
• Direct-fit Mando-style housing and connections simplify removal of the old unit and installation of this replacement
• Single-groove V-belt pulley comes installed for straightforward belt alignment and tensioning
• Marine-duty construction suited to the demands of inboard and stern drive engine compartments

Product Specifications

• Voltage: 12 Volts
• Amperage: 55 Amps
• Regulator: Internal
• Mounting foot: 2 inch
• Pulley: Single-groove V-belt, included
• Cross-reference: ARCO 60050

Replacement Compatibility

This unit fits the Mercruiser MODEL 4.3L Stern Drive as listed. It is the widely used Mando-style 12V 55A marine alternator, cross-referenced to ARCO 60050, and the same alternator services a broad range of Mercruiser, Pleasurecraft, Volvo Penta, OMC, Crusader, Indmar, Marine Power, Hardin, Medalist, and Chrysler Marine applications. Common interchange part numbers include Mercury and Mercruiser 12449, 78403A1, 78403A2, 817119A1, 817119A4, 92497A3, 98555, and 98555A1, along with Sierra 18-5957 and 18-5966 and Marine Power 1210-000. Match the stamped number on your existing alternator against these references to confirm fitment before ordering.

Discover the Perfect Replacement

Keep the electrical system on your Mercruiser MODEL 4.3L Stern Drive charging the way it should. Order this 12 volt, 55 amp replacement alternator today, confirm your cross-reference numbers at checkout, and get back on the water with dependable power for every outing.

During the checkout process, you can choose from expedited services such as overnight delivery to standard ground shipping. We aim to ensure your order is delivered promptly and reliably, wherever you are.

All returns must be made within 30 days of purchase with the invoice. (After 30 days, Interlight credit only, Minimum 25% restocking fee, no returns after 60 days, special items order just for you are not returnable.)

At Interlight, your satisfaction is our priority. We offer a 30-day money-back guarantee on eligible products, provided they are returned in resalable condition with the original invoice.