Overview

The Garmin Reactor 40 Mechanical/Retrofit/Solenoid Corepack is a below-decks autopilot corepack built around a solid-state 9-axis AHRS, made for boats using mechanical, retrofit, or solenoid steering drive setups. The ECU connects to a 12 to 24 Vdc supply, and the system is configured and controlled over NMEA 2000 on your boat. Plan the below-deck layout around the CCU-to-ECU interconnect cable length of 5 m (16 ft.).

On the water, it handles the common day-to-day modes you actually use: heading hold for open-water transits and step turns for course changes. With wind data available to the system, it also supports wind hold plus tack and jibe functions for sailboats.

Drive hardware is selected to match the steering system and is not part of the corepack. If you are pairing this autopilot to a solenoid drive unit or a drive unit not sold by Garmin, rudder feedback is required through a rudder feedback sensor or by connecting to an existing rudder feedback sensor using the appropriate cable. Rudder feedback compatibility is for a typical three-terminal, potentiometer-type sensor, not a frequency-based sensor.

Key features

• Solid-state 9-axis AHRS for heading and motion sensing, with mounting flexibility for the CCU
• Works with mechanical, retrofit, and solenoid steering drive arrangements when matched with the correct drive hardware
• NMEA 2000 integration for setup and control, and for sharing heading and steering data across the network
• ECU power requirement: 12 to 24 Vdc
• NMEA 2000 network power requirement: 9 to 16 Vdc
• CCU mounting guidance: install in a non-submerged location, near the center of the boat, and away from magnetic interference
• CCU-to-ECU interconnect cable is 5 m (16 ft.) and must not be cut
• Drive-unit cabling constraints: drive unit power cables cannot be cut or extended; solenoid power cable runs are fixed-length and cannot be extended

Variants

This corepack is offered in multiple configurations based on the included autopilot instrument at the helm.

The core autopilot components and steering integration remain the focus across the range, while the helm interface differs depending on whether a dedicated control head is included.

• 010-00705-48: Autopilot instrument not included. Control and setup are handled from a compatible Garmin chartplotter on the same NMEA 2000 network, or by adding a dedicated helm control separately.
• 010-00705-49: Autopilot instrument GHC 20. Includes a dedicated GHC 20 helm control with a 4 inch color display for running the autopilot from the helm station.
• 010-02794-02: Autopilot instrument GHC 50. Includes a GHC 50 autopilot instrument with a 5 inch touchscreen for a modern helm interface and quick access to steering modes.

Compatibility and fit

This is a below-deck corepack meant to be paired with the correct steering drive hardware for your boat, whether that is a mechanical drive or a solenoid valve drive arrangement. It is commonly used on boats with direct or cable-actuated steering, as well as retrofit installations where an existing drive unit is being adapted.

If you are integrating with a third-party drive unit or a solenoid drive unit, plan for rudder feedback during the installation. The system supports a three-terminal, potentiometer-type rudder feedback sensor and does not work with frequency-based rudder feedback sensors.

Installation and setup

Start by laying out the CCU and ECU locations so the interconnect cable reaches without splices. The CCU is typically installed on a rigid surface near the center of the boat, and it should be kept away from magnetic sources that can affect heading performance.

At the helm, the system can be run through a dedicated autopilot instrument (when included) or through a compatible Garmin chartplotter connected on the same NMEA 2000 network. Commissioning and calibration are part of any autopilot install, so plan time for dockside checks and a sea trial once steering and rudder feedback are verified.

Electrical and system integration

Power wiring is split between the ECU supply (12 to 24 Vdc) and the NMEA 2000 backbone supply (9 to 16 Vdc). Keep those power feeds separated and protected as part of a clean electrical installation, and route cabling where it will not chafe or live in standing water.

Drive unit power cabling cannot be cut or extended, and solenoid power cabling is also fixed-length, so measure runs carefully before committing to mounting locations. This corepack is a good match for owners building a networked Garmin helm and want an autopilot brain below deck, with the helm interface selected to suit how the boat is operated.