Marine Alternator 12V 55A – Replaces MerCruiser 817119A1 | SKU 57-60050
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You have 30 days to request a return. All sale items are final sale.
A reliable aftermarket replacement alternator for MerCruiser sterndrive and inboard engines. This 12-volt, 55-amp unit replaces MerCruiser OEM part number 817119A1 and is a direct-fit drop-in with an internal voltage regulator, single groove pulley, and 2-inch mounting foot — no additional wiring or regulator changes required. If your charging system is underperforming, showing a low voltage warning, or the alternator has failed outright, this is the correct replacement for the applications listed below.
Compatible Applications
- MerCruiser 5.0L (305 CID) V8 sterndrive engines
- MerCruiser 5.7L (350 CID) V8 sterndrive engines
- MerCruiser 7.4L (454 CID) V8 sterndrive engines
- MerCruiser 8.2L (502 CID) V8 sterndrive engines
- MerCruiser inboard engines equipped with the Delco CS-series alternator and single groove belt drive
- Verify fitment against your engine serial number and parts diagram before ordering — belt routing, pulley count, and mounting foot dimensions must match
Replaces
- MerCruiser OEM: 817119A1
Product Details
- SKU: 57-60050
- Voltage: 12V
- Output: 55 Amps
- Regulator: Internal voltage regulator
- Pulley: Single groove
- Mounting Foot: 2 inches
- Type: Aftermarket direct replacement
- Condition: New
Related Products
- Mercury Alternator (Black) – OEM Marine Engine Charging System
- Quicksilver 70 Amp Alternator – Delco Serpentine – 862031T1
- Sierra Marine Alternator – High-Output Charging System
- PCM 70-Amp Marine Alternator – RA097007
- AC Delco Marine Alternator – High-Output Charging System
Parts Desk Insights
This unit is the right choice when you need a straightforward, cost-effective replacement for a failed or underperforming alternator on a MerCruiser V8 sterndrive with the single groove belt drive configuration. It fits the same footprint as the original Delco unit, so installation is a direct swap — remove the old alternator, transfer the belt and wiring connectors, and torque the mounting foot. The most common issue we see with these is customers ordering without checking pulley groove count: if your engine has a serpentine (multi-groove) belt system, this single groove unit will not fit and you’ll want the Quicksilver 862031T1 serpentine alternator instead. Always confirm your belt type and mounting foot dimension before ordering. At 55 amps, this alternator is well suited to standard house loads on a mid-size vessel, but if you’re running a large inverter or heavy electronics load, consider a higher-output unit such as the Sierra high-output alternator.
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 1-3 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
Returns & Satisfaction Guarantee
We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
To qualify for a return:
Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.