Sierra Voltage Regulator 18-99481 for Mercury Mariner Outboard Engines

The Sierra 18-99481 is a voltage regulator built as a replacement for Mercury Mariner outboard engines. A voltage regulator manages the charging output from the engine's alternator or stator, keeping the electrical system supplied with a steady, controlled voltage for the battery and onboard electronics. Sierra manufactures this component to match the fit, connection points, and electrical performance of the original equipment it replaces on covered Mercury Mariner outboard applications.

This part is sold individually as a direct-fit replacement unit. It is intended for boat owners and marine technicians servicing Mercury Mariner outboard charging systems who need a reliable regulator without sourcing a full OEM assembly. The unit weighs 1.9 pounds as shipped.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-99481
• Product Type: Voltage Regulator
• Compatible Engine Brand: Mercury Mariner
• Application: Outboard Engines
• Weight: 1.9 pounds
• UPC: 808282396039

Fitment

Designed for Mercury Mariner outboard engines.

Replaces (OEM)

No OEM cross-reference numbers are specified for this part.

Frequently Asked Questions

What is the Sierra 18-99481? The Sierra 18-99481 is a voltage regulator designed as a replacement part for Mercury Mariner outboard engines, controlling the charging voltage sent to the battery and electrical system.

What engines does the 18-99481 voltage regulator fit? This regulator is built for Mercury Mariner outboard engines.

How much does the Sierra 18-99481 weigh? The Sierra 18-99481 voltage regulator weighs 1.9 pounds.

Is the Sierra 18-99481 a genuine Mercury Mariner part or aftermarket? The 18-99481 is manufactured by Sierra as a replacement part for Mercury Mariner outboard engines, not an original Mercury Marine branded part.

What does a voltage regulator do on an outboard engine? A voltage regulator, such as the Sierra 18-99481, controls the output from the engine's charging system so the battery and electronics receive a steady, regulated voltage instead of raw alternator or stator output.

What is included when I order the 18-99481? Ordering the Sierra 18-99481 gets you the voltage regulator unit itself.

Can I install the Sierra 18-99481 myself? The Sierra 18-99481 is sold as a direct-fit replacement regulator for Mercury Mariner outboards, and installation follows the same mounting and wiring connections as the original regulator it replaces.

Does the Sierra 18-99481 come with a warranty? Warranty terms for the Sierra 18-99481 voltage regulator are set by Sierra and the selling retailer at time of purchase.

What brand manufactures part number 18-99481? Part number 18-99481 is manufactured by Sierra.

Why would I need to replace my outboard's voltage regulator? A failing voltage regulator can cause overcharging or undercharging of the battery on a Mercury Mariner outboard, and the Sierra 18-99481 is offered as a replacement for that component.