Raymarine ST4000 autopilot malfunction

[ianmartin]

Fluxgate compass bearing swings randomly (<70 degrees) with alarming results. Not due to external magnets nor dependent on ship's course. Installed 2005 but only recently developed this problem. Anybody have similar experiences?

[peterjb]

Yes, my variations were not as large but the fault was traced to the compass memory chip which was replaced under guarantee. My fluxgate compass was installed in 2005 and replaced in 2006. Unfortunately, I think that the problem was starting again at the end of this season!