Sierra Voltage Regulator 18-99404, 10 Amp, Replaces Johnson/Evinrude 584204 for 4/6 Cylinder Cross Flow Outboards

The Sierra 18-99404 is a 10 amp voltage regulator built for Johnson/Evinrude outboard ignition systems. It regulates charging output from the outboard's stator/alternator to protect the battery and onboard electronics from overcharging, replacing the OEM regulator on applicable Johnson/Evinrude Cross Flow engines. The unit is a direct cross reference for the OEM regulators used across a wide range of Johnson/Evinrude 4 cylinder and 6 cylinder Cross Flow powerheads, making it a straightforward like-for-like replacement when an original regulator fails or begins overcharging the battery.

This regulator supports 4 cylinder Cross Flow engines rated 65 JET, 80 JET, 85, 88, 90, 100, 112, 115, and 140 HP, as well as 6 cylinder Cross Flow engines rated 150, 155, 185, and 235 HP. It is designed as a bolt-in replacement for the OEM part, restoring proper charging system regulation without modification to the existing wiring harness.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-99404
• Amperage: 10 Amp
• Weight: 1 pound
• UPC: 808282394356
• Application: Johnson/Evinrude Outboard Ignition System
• Cylinder Compatibility: 4 Cylinder and 6 Cylinder Cross Flow Engines

Fitment

• Johnson/Evinrude 4 Cylinder Cross Flow: 65 JET, 80 JET, 85, 88, 90, 100, 112, 115, 140 HP (1984-1998)
• Johnson/Evinrude 6 Cylinder Cross Flow: 150, 155, 185, 235 HP (1984-1990)

Replaces (OEM)

• 585129
• 585195
• 583529
• 584204
• 878331
• 0583529

Frequently Asked Questions

What does the Sierra 18-99404 voltage regulator do? It regulates the charging current from a Johnson/Evinrude outboard's stator or alternator so the battery and onboard electronics are not overcharged, replacing the engine's original voltage regulator.

Is the Sierra 18-99404 a 10 amp or 6 amp regulator? The Sierra 18-99404 is rated for 10 amp charging output.

Which OEM part numbers does the 18-99404 replace? It cross-references to OEM numbers 585129, 585195, 583529, 584204, 878331, and 0583529.

Will this regulator fit a 4 cylinder Johnson/Evinrude Cross Flow engine? Yes, the 18-99404 fits 4 cylinder Cross Flow engines rated 65 JET, 80 JET, 85, 88, 90, 100, 112, 115, and 140 HP from 1984-1998.

Does the 18-99404 fit 6 cylinder Cross Flow outboards too? Yes, it also fits 6 cylinder Cross Flow engines rated 150, 155, 185, and 235 HP from 1984-1990.

How much does the 18-99404 voltage regulator weigh? The Sierra 18-99404 weighs 1 pound.

Can I install this voltage regulator myself? The 18-99404 is designed as a direct bolt-in replacement for the OEM Johnson/Evinrude regulator, so it connects to the existing wiring harness without modification.

Is the Sierra 18-99404 a genuine Johnson/Evinrude part or aftermarket? The 18-99404 is a Sierra-branded regulator manufactured as a cross-reference replacement for the OEM Johnson/Evinrude regulator, not an original Johnson/Evinrude-branded part.

What ignition system is the 18-99404 designed for? This regulator is built for the Johnson/Evinrude outboard ignition system on applicable Cross Flow engines.

Does replacing the voltage regulator fix an overcharging battery on an outboard? A failed or worn voltage regulator like the original equivalent to the Sierra 18-99404 is a common cause of overcharging, and replacing it restores proper charging regulation.