Description
Sierra International Alternator Conversion Kit 18-5953-1 is designed to upgrade Mercruiser 3.7L (Model 470/485) 4-cylinder aluminum block marine engines. It replaces the notoriously problematic factory stator-charging system and water-cooled voltage regulator with a modern, reliable 68-amp external alternator setup.
Key Product Details
- Engine Compatibility: Fits Mercruiser 224 / 3.7L 4-cylinder engines with serial number 4625580 and up.
- OEM Part Replacement: Directly replaces Mercury Marine part number 804916A1.
- Safety Standards: Marine-grade construction that meets or exceeds USCG, SAE J1171, and ISO 8846 safety standards for ignition protection.
Kit Contents
According to the technical sheets from Go2marine and Marine Engine Parts, this complete low-mount kit includes:
- New 68-Amp Delco-style alternator (Sierra #18-5956)
- Heavy-duty mounting brackets (Sierra #18-5968)
- Alternator drive belt (Sierra #18-5949)
- Crankshaft/flywheel pulley (8.0" Outer Diameter x 2.75" Height)
- Marine-grade wiring harness, mounting hardware, and installation instructions
Critical Installation Notes
- Clearance Requirements: Your boat must have at least 4 inches of clearance in front of the engine to allow room for the new pulley on the existing flywheel.
- Inboard Restriction: This kit is strictly engineered for Sterndrive (I/O) configurations and will not install on true Inboard engine setups.
Starter & Fuse Requirements:
- If your engine features a Delco starter (identified by a round solenoid mounted directly on top of the starter body) or has a serial number 6902288 and up, a separate 90 Amp Fuse Kit (Sierra #18-8220) is required for safety.
- Engines using a Prestolite starter with a remote bulkhead-mounted solenoid do not require this extra fuse kit.
Specifications
- California Residents:
- WARNING Cancer and Reproductive Harm - P65Warnings.ca.gov
