Sierra 18-5953-1 Alternator Conversion Kit

Upgrade Your Mercruiser 470 with Reliable Power

Boat owners with older Mercruiser 470 aluminum block engines know the frustration of unreliable charging systems. The stator setup with its water-cooled voltage regulator often fails under demanding marine conditions, leaving you with dim lights, weak batteries, and stalled outings. This conversion kit transforms that outdated system into a robust alternator setup, delivering consistent 68 AMP output to keep your electronics humming and batteries topped up, even during long cruises or heavy accessory loads like trolling motors and fish finders.

Engineered for serial numbers 4625580 and higher, this kit ensures plug-and-play simplicity on your V8 powerhouse. You'll notice improved starting reliability and reduced alternator wear thanks to modern diode technology that handles voltage spikes from saltwater exposure and engine vibrations.

What's Included for a Seamless Swap

• High-Output 68 AMP Alternator: Built tough for marine environments with sealed bearings and corrosion-resistant housing.
• Mounting Brackets (18-5968): Precision-machined for exact fit, no drilling or modifications needed.
• Pulley and Belt Alignment: Optimized for OEM belt routing to prevent slippage and overheating.
• Complete Wiring Harness: Color-coded and labeled for foolproof connections, bypassing old stator wiring headaches.
• Hardware Kit: Stainless steel fasteners that resist rust in harsh bilge conditions.
• Detailed Instructions: Step-by-step guide with photos, saving hours of guesswork.

Pro Tip: Starter Check

Before diving in, pop the hood and eyeball your starter. Delco models with the round solenoid mounted directly on the starter call for an additional fuse kit to protect the system. Prestolite starters with remote solenoids skip this step entirely—clean and straightforward.

Why Switch to an Alternator System?

Stator systems were fine for basic setups decades ago, but today's boats demand more. This upgrade delivers:

• Higher Amperage: 68 AMPS versus the stator's typical 20-30, perfect for GPS, radios, and pumps.
• Maintenance-Free Operation: No brushes to wear out or water cooling to leak.
• Better Cold Cranking: Stable voltage for effortless starts in chilly mornings or after sitting idle.
• Longevity Boost: Diodes rectify AC to DC more efficiently, extending battery life and reducing recharge times.
• DIY-Friendly: Most swaps take 2-4 hours with basic tools—no marine mechanic required.

Real-world result? Fewer dockside dramas and more time on the water. Anglers report cranking winches and livewells without a hitch, while cruisers power inverters for coffee makers effortlessly.

Installation Insights from Seasoned Boaters

Start by disconnecting the battery to avoid shorts. Remove the old stator and regulator—often just a few bolts and clips. Mount the new brackets, slide in the alternator, route the wiring, and tension the belt. Test at idle and under load to confirm 13.8-14.4V output. Common pitfalls? Over-tightening belts (use a gauge) or ignoring corroded grounds—clean them shiny for peak performance.

"Swapped mine on a '92 Merc 470 last summer. Night-and-day difference—no more voltage drops trolling at night." – Lake Michigan Captain

Frequently Asked Questions