but other issues. You said the compass display changes when you turn the fluxate. The flashing C only means that you have not selected AUTO.

You have posted some conflicting information.

Your original post said that the rudder moves when you hit plus or minus but the display does not change - that is very strange. When you press AUTO the display will not change - that is your selected course. The display should change when you press + or -. When you say it does not hold course, does the rudder move at all? There is a knob that adjusts helm response. Clockwise increases response. If the rudder is moving but not enough turn up the rudder response. If the servo makes noise but the chain does not move either the gears or the clutch is shot.

If the rudder does not move at all and/or the display does not change when you hit + or - your course computer or maybe your drive has problems. If it's the computer it is time to replace it. I know of only one guy that fixes the old course computers and he is in Martinique.