Choosing · 6 minute read
Buying a second-hand autopilot
What to inspect before buying a used marine autopilot in Australia: drive wear, missing sensors, network generations, spares for discontinued units.
A used autopilot can be a genuine bargain or an expensive box of obsolete parts, and the difference is usually visible in ten minutes if you know what to look at. The mechanical half of these systems is robust and repairable. The electronic half is where obsolescence bites, because a course computer that cannot talk to anything you own is scrap whatever its condition.
The rule of thumb for the Australian market is to buy drives second-hand and be careful about electronics. A sound or hydraulic pump has decades of life in it and is expensive new. A ten-year-old proprietary course computer with a cracked keypad is a different proposition.
Key facts
- Buy used
- Drives, pumps and rams, which are mechanical and repairable
- Be careful
- Course computers and control heads on dead network standards
- Check first
- That every sensor and cable in the system is actually included
- Test
- Run the drive under load before money changes hands
- Hybrid
- An old drive with a new course computer often makes sense
- Prices
- Highly variable; treat any figure as indicative only
Used autopilot drive wear and component failures
Drive motors wear at the brushes and bearings, and a tired one draws more current and runs hot. Belts on wheel pilots glaze and slip. Clutches drag or fail to hold. Hydraulic pumps weep past a shaft seal and eventually let air into the steering. Control head keypads go mushy or stop responding to one particular button, usually the one you need in a hurry.
The other classic is corrosion at the connectors. Look at every plug and every crimp on offer. Green powder around pins, a stiff cable where water has wicked up inside the insulation, or a connector that has been taped rather than replaced all tell you the same story about how the boat was kept.
Cosmetics matter less than you think on a drive and more than you think on a control head. A scratched ram is fine. A control head that has been baked in the sun until the screen is delaminated and the keypad legends have gone is a part you will replace.
Generations and network compatibility
This is where most used-autopilot money is wasted. Raymarine has run through original SeaTalk, then , and now sits on underneath SeaTalkng, and the plugs, voltages and messages are not interchangeable without the right converters. Navico gear moved from SimNet to NMEA 2000 connectors, and Furuno equipment may expect a NavNet environment for full integration.
Before you buy, write down what you already have on the boat, what protocol the used part speaks, and what converter or adaptor cable stands between them. Then price those adaptors, because a bag of converters can cost more than the bargain you are chasing.
The same applies to the pilot's own family. A course computer, control head and heading sensor from the same generation will commission cleanly. Mixing generations sometimes works and sometimes produces a system that runs but will not calibrate, which is the worst outcome of all.
Ask what it was removed from, and why
Identify missing autopilot sensors, controls and cables
Autopilots are systems, not single boxes, and used listings are routinely incomplete. The , the heading sensor, the dedicated power cable, the bracket that carries the drive, the network cables and the terminators are all things that vanish between the boat and the marketplace advertisement.
Price the missing pieces before you commit. A rudder feedback unit or a heading sensor bought separately can be a large fraction of the cost of a complete used system, and some parts are simply not available for discontinued models.
- Course computer or drive unit with its mounting hardware
- Heading sensor and its cable, with the mounting bracket
- Rudder reference transducer and linkage, if the system needs one
- Control head, bezel and the flush-mount hardware
- Power cable of the correct gauge and the original fuse or breaker
- Network cables, tees and terminators of the right generation
- Manuals, or at least the model and serial numbers so you can find them
Discontinued gear: Autohelm, early Simrad and friends
Plenty of Australian boats still steer beautifully on Autohelm-era equipment, and the mechanical parts can often be kept going. Motors can be rebuilt, belts and clutch plates are sometimes still available, and specialist repairers exist who know these units well.
Electronics are the limit. Once a course computer dies and the manufacturer no longer supports it, you are relying on the used market for a replacement of the same vintage, which means buying another unit of unknown history. That is fine for a day sailer on a bay and not fine for a boat going offshore.
If you like an old system, buy a spare while they are still around. A second complete control head, bought for a modest sum at the same time as the pilot, is cheap insurance against the one part that will end the system's life.
Test a used autopilot before purchase
Insist on seeing it work. For a tiller pilot, that means power on a bench supply, run the ram end to end several times, and push back against the pushrod by hand while it drives. It should hold firmly without stalling or chattering. Listen for a drive that changes note at one point in its travel.
For a below-deck drive, ask to see it installed and running if it is still on a boat, which is far more informative than a garage test. On the bench, spin the output and feel for notchiness, check the ram for pitting and the seals for weeping, and look at the mounting feet for cracks or elongated bolt holes.
For the electronics, power up the control head and step through the menus. Check every key. Look for a self-test or diagnostic page and note any stored alarms. If the seller will not power it up, assume it does not work.
- Run the drive through full travel at least ten times, watching current if you can
- Load the drive by hand and confirm it does not stall or slip
- Press every key on the control head, including the soft keys
- Check the serial numbers against the manufacturer's current support list
- Inspect all connectors for corrosion and all cables for stiffness
- Ask for the original invoice or install date if there is one
Used autopilot prices and partial-system upgrades
Used prices in Australia vary enormously with condition, completeness and whether the model is still supported, so treat any number as indicative and confirm with a dealer what a new equivalent costs before you decide a used unit is a bargain. As a guide, a complete used tiller pilot in working order sells for a fraction of new, while a used below-deck drive can still be a significant sum because the new price is high.
The hybrid that often makes the most sense on an older cruising yacht is keeping the existing below-deck drive, which is mechanically sound and correctly installed, and fitting a modern course computer, heading sensor and control head to it. Manufacturers publish drive compatibility for their current course computers, and many older linear and hydraulic drives are still on those lists.
That approach buys modern adaptive steering, a current network and supported parts for a fraction of a full replacement, and it avoids the hardest part of any autopilot installation, which is getting a drive properly mounted and aligned to the quadrant. Ask an installer to confirm compatibility before you buy anything.
Questions
Frequently asked
Is a used autopilot a false economy?
Not for the mechanical parts. Drives, rams and pumps are expensive new and repairable when worn, so a sound used one is often good value. The risk sits in the electronics, where an unsupported course computer or a dead network standard can make the whole system unusable.
Can I mix brands in one autopilot system?
The pilot's own components, meaning the course computer, drive, heading sensor and control head, should be from one manufacturer and ideally one generation. What you can mix is the surrounding data: most current pilots will accept position, wind and depth over NMEA 2000 from another brand's instruments. Confirm the specific combination with a dealer before buying.
How do I know if a model is still supported?
Check the manufacturer's current product and support pages for the model and note whether spare parts and software updates are still listed, then ask an Australian dealer what they can still get. Support for a model usually outlasts its production by some years, but that window closes quietly. If nobody can supply a control head, treat the system as end of life.
What is a used autopilot worth in Australia?
Too variable to state usefully, because condition, completeness and continuing support move the price enormously. The sensible method is to price a new equivalent system from a dealer, then decide what discount makes the used risk worthwhile to you. Remember to add any missing sensors, cables and adaptors to the used price before comparing.
Should I get an installer to look at it first?
For a below-deck system, yes. An hour of an installer's time to confirm drive compatibility, network generation and the parts list is cheap against buying an incomplete system. Many installers will also tell you whether a particular course computer is still worth commissioning.
Practise autopilot operation with an instructor
Habits are learned at the helm with someone watching. The training section explains what a good instructor covers and where to find one in your state.