Autohelm Jitters

[DOILY]

My Navico TP100 has developed the jitters. On the boat and on the bench with a good 12v supply, when in auto mode, the pushrod constantly moves in and out in apparently random short strokes. It only stops if I grab the unit and hold it perfectly still. It's as if the pushrod is responding to all movements, not just deviations from course.
I have dismantled the unit and checked as best I can for signs of damage and water ingress, etc.
Does anyone have any thoughts on what could be causing the strange behaviour please?
T.I.A.

 

[wallacebob]

You can adjust sensitivity; refer to manual. Stops constant adjustment.

 

[Refueler]

Also it should take time to adjust to sea state ...

 

[DOILY]

You can adjust sensitivity; refer to manual. Stops constant adjustment.

Thank you for your help. I should have added that it is set at lowest sensitivity.

 

[shanemax]

Last week I took mine apart and greased it as it was making a loud whine (not a quiet whine as is usual) I used a spray grease. Please try that as it could be the long jack screw jamming. I do mine every so often as the jack screw has to do all the hard work. Just out of interest why is it set to the lowest setting as it comes out of the factory mid set 4-5.

 

[Refueler]

Personally.. I would revert all settings such as sea state to default ... mid point.

Give it a decent time to settle and sort itself ....see what happens.

 

[Iliade]

Electrical fault on the compass connections? Dirt on the LED/receiver, if it uses that technology. If it is out of warranty, open it up and check for moisture or corrosion.

 

[DOILY]

Last week I took mine apart and greased it as it was making a loud whine (not a quiet whine as is usual) I used a spray grease. Please try that as it could be the long jack screw jamming. I do mine every so often as the jack screw has to do all the hard work. Just out of interest why is it set to the lowest setting as it comes out of the factory mid set 4-5.

Thank you for your reply. I've used it on the boat for the past 3years at mid set sensitivity. I lowered the sensitivity to see if it had any effect on the jitters. It didn't.

 

[roaringgirl]

I think if I tried to run mine without the rudder-angle sensor connected, it would behave similarly.