Furuno Navpilot 300


New member
I have the Furuno Navpilot 300 linked to a 2019 TZTouch 2 on my Carolina Classic 28. Several months ago, while the autopilot was engaged, the rudders went full over full port. Shortly thereafter after the error message “rudder deviation alert” followed by “check drive motor change circuit “.

I conducted Honour Marine who did my electronics installation and they came down and did the dockside tests which all checked out for fine. We took the boat out and tested it and everything worked perfectly until a couple of trips later when it failed again with the same error message.

We sent the processor into Furuno who benched tested it and could find nothing wrong.

We reinstalled it, did the various setups/check’s which it all passed only to have it fail midway through our next trip. Again same symptoms/error messages.

Then again working with Honour Marine we replaced sequentially the following components:

1. Processor
2. Control Unit
3. Hydraulic Pump

After each we went through the dockside setups and checks (which it passed) only to have it fail one or two trips later each time again with the same symptoms/error messages.

Prior to our most recent trip, we went into the Parameters and changed from Self Learning to Manual. From there, we adjusted the various settings to broader tolerances hoping that we could minimize the amount of “work” the autopilot was doing. Again roughly midway to two thirds it failed the same way.

Thoughts/Suggestions? My arm, never mind my crews, are going to fall off….
If the RRU isn't slipping then it makes no sense. I would recommend getting with tech support and have them send you a special USB that can be inserted into the pilot to record what is happening. After the error happens; pull the USB and send it back to support. At this point I think something is pulling your heading. If I was to guess, you have a flux gate like the PG700 that is being pulled by something.
Thank you Johnny and yes we do have the PG700 heading sensor. I am out on a trip right now but I sent your response to the guys at Honour Marine. We are going to talk when I get back home. Thank you very much for your help.

Very sorry for the delay in getting back to you. We are just finishing up our fishing and that combined with the normal year end maintenance has had us very busy I’m afraid. In answer to your question, I assume you mean our steering hydraulic pump and the answer is yes.

Good news though. Shortly after our exchange in September the folks at Honour Marine, determined the port rudder sensor was failing intermittently. The cause as best as we can determine was the toggle bolts that hold the stern lazerette hatch down had worked loose and we were dumping copious amounts of water directly on top of it (the sensor) which over time led to perhaps some sort of water ingress and/or localized corrosio. Anyway, we replaced them both and the wire leads (to be safe) and everything is working great now.

Thank you again for your help and again I apologize for not responding sooner. Besides producing superb products, Furuno and here in San Diego Honour Marine’s, customer support is second to none. That’s a critical consideration and sometimes overlooked when deciding on what electronics to outfit your boat with. Now in our 5th season, we are very pleased with the decision we made.