Raymarine forum

Last year, my system worked perfectly. Then I had my steering serviced and my rudder position sensor was left disconnected. This offseason I got everything reconnected and calibrated.

On my last trip, the autopilot engaged, but would not hold exact course. After 15-20 minutes it was off 20 degrees from my standard compass despite the pilot head showing the desired heading.

If it is relevant, my system used to fully disengage manual steering once the auto was engaged. Now, the manual system is not disengaged.

Any ideas on troubleshooting?

Welcome to the Raymarine Forum Travis,

If after sea trialing the autopilot to establish its sensed deviation and then aligning the compass, should the heading reported by the autopilot differ significantly (as you have reported) from the vessel's fluid filled and properly calibrated compass, then it is possible that the autopilot's fluxgate compass may be failing. Please click here to view a FAQ addressing how to test the autopilot's fluxgate compass.

Regarding the steering symptom, what model of autopilot drive unit is installed onboard?

I will test the compass this weekend.

I have a Type 1 drive unit.

Noted.