Simrad AP11 Autopilot Issue

[Richard77]

I have a AP11 head unit for a autopilot which is hook up to my Garmin 8610XSV. My last trip out last year my autopilot showed Compass Failed. Today I tried figuring out what was causing it. The autopilot will say Compass Fail at times now but the autopilot display regardless if it shows compass fail or not the compass reading continuously is changing by many degrees. When this occurs with the autopilot my nav chart on my garmin continuously moves around too until I turn autopilot off. Before this happened I did have issues with the AP11 head unit not showing anything on the display it would have to be on most of the day before this would happen. Once I would turn it off for several hours it would work fine. I figured it was possibly getting too hot and causing this. I have cleaned all wires as a precaution on junction box also cleaned connectors on head unit inspected the connectors inside flux gate compass everything seems fine. I’m thinking it could possibly be head unit since I had a separate issue with it. Has any experienced this issue before?

 

[oguidry]

What heading sensor are you using?

 

[Richard77]

I located two of the black boxes on my boat. I never looked at the tag but it seems one is the RFC35 fluxgate and other seems to be CDI35 Course interface.