Garmin Autopilot oscillates every few minutes

[Brian C]

I have a Garmin GPSmap 7612xsw with a Garmin Autopilot with remote.
When autopilot is engaged, every 3 minutes or so, it will cause the boat to steer hard back and forth about 20 degrees in either direction for about 30 seconds. If I do nothing to control it, it will end up back heading in the right direction, but way off course.
I have done the updates and have done 3 dealer calibrations under Garmin factory assistance. (straight line, long circles, etc.) Nothing seems to fix it.
Any ideas?
Regards,
Brian
2016 Ranger R25sc "Tug Life"

 

[Bruce Moore]

Bumping post delayed in moderation queue.

 

[Ralf H]

Hi Brian,

Honestly haven't seen this issue before, but since you're working with Garmin directly, I would ask them about potential issues with the autopilot pump. I suspect that you are not having any issues while under way without using the autopilot. Garmin has had issues in the past with autopilot pumps causing heading/steering issues and it would be on the top of my list to take a look at the pump. Garmin would need to prescribe what tests would be necessary to determine that, but that's where I would start. Hope this helps.

Cheers,

Ralf