Sierra 18-99412 Johnson/Evinrude Voltage Regulator, 10 Amp, Replaces 584476, 585001

The Sierra 18-99412 is a 10 amp voltage regulator built for Johnson/Evinrude outboard engines. It manages charging system voltage output from the engine's alternator/stator, protecting the battery and onboard electronics from overcharging while maintaining consistent electrical performance. The housing is aluminum, providing durability and heat dissipation in the marine engine compartment where the regulator is mounted.

This regulator is a direct fit for Johnson/Evinrude 2, 3, and 4 cylinder outboard engines across a range of horsepower ratings, including 2 cylinder models with a three-wire trigger, 3 cylinder models using the S.L.O.W. (Speed Limiting Overheat Warning) system, and the 4 cylinder 4-stroke 60 degree engine. It replaces OEM part numbers 584476 and 585001, making it a straightforward swap for boat owners repairing a failed or degraded factory regulator. At 0.6 pounds, it is a compact, lightweight component that mounts to the engine using the factory hardware locations.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-99412
• Weight: 0.6 pounds
• Material: Aluminum
• Amperage: 10 Amp
• Mounting Type: Transom Mount
• Fuel Type: Gasoline
• Engine Type: 4 Stroke
• OEM Equivalent Part Number: 584476, 585001
• UPC: 808282394431

Fitment

• Johnson/Evinrude 40 and 50 HP (2 cylinder with three-wire trigger), 1992-2005
• Johnson/Evinrude 25, 40, 50, 60, 65 and 70 HP (3 cylinder with S.L.O.W.), 1992-2001
• Johnson/Evinrude 105 HP (4 cylinder 4-stroke 60 degree engine), 2000-2001

Replaces (OEM)

• 584476
• 585001

Frequently Asked Questions

What engines does the Sierra 18-99412 voltage regulator fit? The Sierra 18-99412 fits Johnson/Evinrude 40 and 50 HP 2 cylinder outboards with a three-wire trigger, 25, 40, 50, 60, 65 and 70 HP 3 cylinder outboards using the S.L.O.W. System, and the 105 HP 4 cylinder 4-stroke 60 degree engine.

What OEM part numbers does this regulator replace? Sierra 18-99412 replaces OEM part numbers 584476 and 585001, so it is a direct swap for either of those original Johnson/Evinrude regulators.

How many amps is the 18-99412 rated for? This regulator is rated at 10 amps, matching the output of the Johnson/Evinrude charging systems it is designed to serve.

How much does the 18-99412 weigh? The Sierra 18-99412 voltage regulator weighs 0.6 pounds.

What material is the regulator housing made of? The housing on the 18-99412 is aluminum, which helps dissipate heat and resist corrosion in the engine compartment.

Will 18-99412 work on a 2 cylinder Johnson/Evinrude engine? Yes, it is compatible with Johnson/Evinrude 40 and 50 HP 2 cylinder engines that use a three-wire trigger.

Does this regulator fit 3 cylinder Johnson/Evinrude outboards? It fits 25, 40, 50, 60, 65 and 70 HP 3 cylinder Johnson/Evinrude engines equipped with the S.L.O.W. Speed limiting overheat warning system.

Is the 18-99412 compatible with 4-stroke engines? Yes, it fits the 105 HP 4 cylinder 4-stroke 60 degree Johnson/Evinrude engine in addition to the 2 and 3 cylinder applications.

What fuel type is this regulator designed for? The Sierra 18-99412 is designed for gasoline-powered Johnson/Evinrude outboard engines.

How is the 18-99412 mounted on the engine? This regulator uses a transom mount configuration on the outboard engine.

Is 18-99412 a genuine Sierra part? Yes, 18-99412 is the Sierra manufacturer part number for this Johnson/Evinrude voltage regulator.