Sierra 18-99413 Regulated Rectifier - Replaces 153-3408, 580841 - Johnson/Evinrude 2/3/4/6 Cyl 50-235 HP

The Sierra 18-99413 is a regulated rectifier built as a direct replacement for Johnson and Evinrude outboard engines that use a rectifier-based charging system. It takes the raw AC output from the outboard's alternator/stator, converts it to DC, and regulates the voltage so the battery is charged correctly without being overcharged or damaged. This is a core charging-system component, and a failed or unregulated rectifier is one of the most common causes of a marine battery that will not hold a charge or an engine that runs down its battery over time.

Sierra 18-99413 is built with a metal housing for heat dissipation and durability in the marine engine compartment, and is designed as a straightforward swap for the outboard charging systems it is intended to service. It covers a wide span of Johnson/Evinrude outboards across 2, 3, 4, and 6 cylinder configurations, making it a common shelf item for shops and owners servicing older outboard charging systems.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-99413
• Weight: 0.3 pounds
• Material: Metal
• Operation Mode: Electric
• Mounting Type: Engine mount
• Fuel Type: Gasoline
• Maximum Horsepower: 235 horsepower
• UPC: 808282394448

Fitment

• Johnson/Evinrude outboards, 2/3/4/6 cylinder, 1969-2000, 50 to 235 HP (rectifier-equipped charging systems only)

Replaces (OEM)

• 153-3408
• 580841

Frequently Asked Questions

What does the Sierra 18-99413 rectifier do? It converts the AC output from a Johnson/Evinrude outboard's stator into regulated DC current, charging the battery correctly while protecting it from overcharging. Part number 18-99413 is a direct fit for outboards using a rectifier-based charging system.

Which engines does the 18-99413 fit? Sierra 18-99413 fits Johnson/Evinrude outboards from 50 to 235 HP across 2, 3, 4, and 6 cylinder configurations, covering engines built from 1969 through 2000 that use a rectifier (not an alternator with a separate voltage regulator).

Is 18-99413 the same as part number 153-3408 or 580841? Yes, the Sierra 18-99413 is a cross-reference equivalent for OEM/aftermarket numbers 153-3408 and 580841, so it can be used as a direct replacement for engines calling for either of those part numbers.

How much does the rectifier weigh? The Sierra 18-99413 regulated rectifier weighs 0.3 pounds.

What is the rectifier housing made of? It has a metal housing, which helps dissipate the heat generated during the AC-to-DC conversion and voltage regulation process.

How is the 18-99413 installed? It is an engine-mount component that installs in place of the existing rectifier on compatible Johnson/Evinrude outboards, wiring into the existing charging circuit; always confirm your engine uses a rectifier-only charging system before ordering.

Will this work on an engine with a separate alternator and voltage regulator? No. The Sierra 18-99413 is designed for engines using a rectifier only; it is not intended for charging systems that use a separate alternator and regulator setup.

What symptoms indicate the rectifier needs to be replaced? A battery that will not hold a charge, runs down during use, or shows erratic charging voltage is a common sign of a failing rectifier on Johnson/Evinrude outboards in the 50-235 HP range that 18-99413 services.

Does the 18-99413 include mounting hardware? The listing covers the regulated rectifier unit itself, part number 18-99413; confirm hardware needs against your specific engine before installation.

Is this a genuine Sierra part or aftermarket? Sierra 18-99413 is sold under the Sierra part number and functions as a cross-reference replacement for OEM numbers 153-3408 and 580841 on applicable Johnson/Evinrude outboards.