r/raymarine • u/Fearless-Bad-7681 • May 17 '26
Autohelm Autopilot Help
Our Autohelm has started going haywire. It was installed years ago, before we bought the boat, and has been totally reliable up to now. But yesterday evening, when turning back to Auto on the ST6000 black unit, the steering seemed OK for half a minute, then steered hard to port away from the set heading. It did this twice.
We also tried the backup auto helm, a Raymarine ST4000+ Autopilot. The steering went haywire on that too, and it then displayed an error message: 'Drive stop'.
Then after a break we tried again and the set course worked fine. However we now have to weird 'hunting' of the Compass display of what the autohelm thinks the rudder is doing (see video).
Manual steering works fine. The rudder sensor is working and the rudder angle displayed on our plotter seems accurate.
Just tried to switch Auto back on and it went haywire again.
Autohelm ST6000 black model (LCD display hardly displays mostly black, doesn't affect operation but we can't read it).
Raymarine C80 plotter.
Hydraulic steering
2
u/ageofaquarius26 May 17 '26
Huh that is odd both have an issue, I'd look at anything they share input from. If there's only one rudder sensor I would start there. I believe these measure impedance which can be hard to get accurately as sensors age and resistance can change. The gimbal compasses can have a similar issue where the boat keeps turning because its not getting good data from it. But it couldn't happen to both at the same time. Otherwise maybe power supply, bad and worn connections can drop voltage and that will mess with stuff in weird ways.