Overview

The Simrad 000-13250-001 is the NAC-3 high-current course computer that runs the drive side of a Simrad autopilot system, with a 30 A continuous (50 A peak) motor output for larger steering loads. It sits below decks, takes steering sensor data, and powers a hydraulic pump, mechanical drive unit, or solenoid valve setup so the pilot can hold a heading smoothly.

This unit is commonly used on boats 10 m (33 ft) and up. It supports NMEA 2000 networking for integration with autopilot controllers and compatible multifunction displays, and it also accepts NMEA 0183 input when you need to bring in legacy data sources. A dedicated clutch output (3 A max) is available for drive arrangements that require it.

Key features

• High-current drive output rated 30 A continuous and 50 A peak for running compatible pumps and mechanical drive units
• 12/24 V DC power input for common onboard electrical systems
• Dedicated clutch output up to 3 A for drive clutch or bypass control where required
• Supports Simrad Continuum steering technology used in Simrad autopilot systems
• NMEA 2000 connectivity for autopilot controllers, compatible displays, heading sensors, and rudder feedback integration
• NMEA 0183 input for bringing select data into the autopilot system
• Compatible with reversible pump and motor drive types, plus solenoid valve steering configurations
• Supports Simrad RF25 and RF300 rudder feedback units, with virtual rudder feedback available for installations where a physical sensor is not used

Compatibility and fit

NAC-3 is a course computer for below-deck autopilot installations where the drive system needs higher current handling. Match it to the type of steering actuator on board, whether that is a reversible hydraulic pump, a rotary or linear mechanical drive, or a solenoid valve steering arrangement.

It is one piece of a complete autopilot system. Plan on a networked autopilot controller or compatible display, a heading source, and the correct drive unit for your steering. If you are using rudder feedback, confirm your sensor type and mounting approach before wiring.

Electrical and system integration

On the network side, NAC-3 ties into a NMEA 2000 backbone so it can exchange heading and steering data with the rest of the system. It also provides NMEA 0183 input when you need to feed specific sentences from a separate device.

Power is supplied from a 12 V or 24 V DC source. Keep the supply wiring sized for the drive load, route it away from ignition components and high-heat areas, and secure it so it cannot chafe in vibration-prone lockers.

Installation and setup

Mount the unit in a protected below-deck location where it stays dry and has room for cable bends and service access. The housing footprint is approximately 211 x 195 x 65.5 mm (8.31 x 7.68 x 2.58 in), so it fits well on a bulkhead or inside a dedicated electronics space near the steering equipment.

When wiring solenoid valve systems, pay attention to how the solenoids are powered. Externally powered solenoids may require isolating relays, which helps avoid backfeeding and keeps control signals clean during operation.

What’s included

• NAC-3 autopilot computer
• Fixing screws (4)
• Micro-C drop cable (male), 0.6 m
• Micro-C T-Joiner
• Connectors (7)
• 30 A fuse
• Warranty card and literature pack

Use cases on board

This course computer is a practical match for cruising boats, sportfishing rigs, and performance sailboats that run larger steering actuators and want the pilot drive handled below decks. It also fits repower and refit jobs where an existing Simrad network is already in place and the drive load calls for the NAC-3 current rating.

Maintenance and care

After the first few outings, re-check terminal tightness, cable support, and strain relief around the drive wiring. Periodically inspect for moisture intrusion in the mounting space and look for chafe where harnesses pass through bulkheads or near moving steering components.