Furuno CH503 to CH502 Autopilot Cable Assembly, 10 Meter

When you're wiring up a Furuno CH502 autopilot, the CH503 transceiver has to talk to the control unit, and this is the cable that makes that happen. It's the genuine Furuno 001-471-550-00 assembly, pre-terminated at both ends and cut to a 10 meter run. That's 32.8 feet, enough to reach from a helm-mounted CH502 down to a CH503 mounted below deck or back in the engine room on most boats.

The CH502 is the control unit you actually touch, the brains at the helm. The CH503 is the transceiver that does the heavy lifting out of sight. Between them runs a fair bit of data, and Furuno spec'd this exact assembly to carry it cleanly. Get the link right and the rest of the system behaves. Get it wrong and you'll chase gremlins for a weekend.

Why buy the factory cable instead of splicing your own? Because the connectors are keyed and pinned exactly the way the CH502 and CH503 expect them. We've seen intermittent drive faults and heading glitches traced right back to a home-made cable with a single pin off. When the autopilot is the thing steering your boat, that's not where you want to save twenty bucks. This assembly plugs in, seats with a click, and you're done.

A few things are worth knowing before you pull this cable. Keep the run clear of engine harnesses and VHF coax. Autopilot data doesn't love sharing a bundle with high-current or RF wiring, and crossed signals can show up as small heading errors that drive you nuts on a long passage. Run it in its own path where you can. On longer boats some installers add a ferrite choke mid-run when they're chasing the last bit of clean data, though most 10 meter installs don't need it.

The connector at the transceiver end sits where moisture likes to find it, so treat it right. A wrap of good heat-shrink and a dab of dielectric grease on the pins goes a long way toward keeping corrosion out over the seasons. And anywhere the cable passes through a bulkhead or rubs a stringer, give it chafe protection. On trawlers running this from the flybridge down to the engine room, we'd put the whole run in conduit and forget about it.

Ten meters covers most installs comfortably. On a 30 to 40 foot sailboat with the transceiver tucked below deck, you'll usually have a little slack to coil and secure, which is exactly what you want. Tight cockpits on smaller boats can make 10 meters feel long, so plan your coil ahead of time. If your run is genuinely shorter or longer, Furuno offers this cable in other lengths, so match the part to your actual measured distance rather than forcing this one to fit.

This is a replacement and install part, plain and simple. If your original cable got pinched, corroded, or chewed, or you're doing a fresh CH502 and CH503 install and need the interconnect, this is the piece. It's specific to that Furuno pairing, so it isn't a general-purpose network cable and it isn't meant to run non-CH series gear. Verify the pin alignment before you plug in, seat both ends fully, and your autopilot has the clean, reliable link it needs to do its job.

Furuno has been building marine electronics that survive real conditions for decades, and the small parts matter as much as the big ones. An autopilot is only as dependable as its weakest connection. This cable isn't glamorous, but it's the link that lets the CH502 and CH503 work together as the system Furuno designed. Order the right length, install it clean, protect the connectors, and you can put it out of mind, which is exactly what you want from a part that helps steer your boat.