The other day we change our old Autohelm type 300 course computer to a Raymarine S3G, still keeping the old Autohelm ST 7000 control unit. It all started very well it kept the course very straight and had no problem even though the wave was rather high and wind only moderate, except that the compass reading was almost 180 degree wrong.
Then after a while the Autopilot goes totally berserk, steering away totally uncontrolled, we put it in stand by and then Auto again it worked fine for ca 24 h, then berserk again.
When later at harbor we notice that in Stand by mode the compass suddenly gave reading all over the place, it change every second all over the 360 degree, not strange that it does not steer well.
Does anyone have experienced similar behavior? Anyone know the remedy for such behavior?
Paul on S/Y Kerpa SM#259 currently in Gibraltar