I have both a Garmin Chart Plotter/multi-function unit and separate auto pilot unit. Everything works good until i turn on the auto pilot and try to engage it. The "boat" icon on the multi-function screen then points in a different direction and basically the auto pilot chases that heading. I have tried it both with a course plotted and just heading hold and same result. I have tried various other things and it seemingly does not help. Any thoughts or ideas??