Fluxgate compass went bonkers...

[DougM]

Odd thing yesterday, the Fluxgate compass in my autopilot decided to point every way but the correct way. Sailing 270 magnetic in standby mode, it suddenly decided to indicate 090, then 030, then 197, all without a course change on my part. I have not had that happen since the original calibration years ago. Looks like a recalibration took care of the problem, but I can't determine a root cause. There is nothing metallic in the compass location ( other than the usual diesel engine, cast iron keel and batteries a couple of feet away that have always been an inherent part of the boat).

Anybody have any thoughts on causes?

 

[bananabender56]

No idea about the cause but my compass went off about 2 weeks ago and is permanently 40 degrees out from the mag compass, meaning on the chart plotter the boat is crabbing. What brand/model do you have?

 

[kloudie1]

I have had that with dirty connections on the control head of the 4000+. Those itty bitty push connectors can go wonkey after a few years. usually pulling and re-installing the push connectors does the trick.

 

[northptsailor]

My auto pilot became very erratic on one of my first trips of the season a few years ago. When I looked under the settee to check on it"s connections I suddenly felt really stupid as I stared at the gallon metal varnish can that I had put in the storage space with the fluxgate to "temporarily" get it out from under foot! Lesson learned - always remember where the flux gate is when storing metal objects.