Raymarine Autopilot problem,

[bigwow]

For various reasons Bigwow has not been used for 7yrs. It has been used as a caravan and when lefy has a dehumidifier left on so there has been no damp. Fitted wirh Raymarine s2g pilot, rudder sensor, fluxgate compass. ST8002.
When switched on the rudder is showing 30 degrees out and the compass is way out.
Any advise where to start?
Thanks John

 

[Stingo]

Sounds like you need to calibrate it. Instructions on the procedure are in the manual

 

[C08]

I used to lust after BW when it was in the boatyard at Fiddlers Ferry. I hope you sort the autopilot -it sound like a re-calibration problem similar to the problem I had with mine.

 

[bigwow]

Re-calibration of the compass I can go with, however the rudder indicator is a mechanical rod from the tiller to the unit, before I start messing about altering the length of the rod I just wondered if there could be any reason it could have gone 30 degree out just sitting there.

I used to lust after BW when it was in the boatyard at Fiddlers Ferry. I hope you sort the autopilot -it sound like a re-calibration problem similar to the problem I had with mine.

Still not finished!

 

[howardclark]

From memory the fluxgate compass has 3 sectors- I ended up replacing one when one of the sectors was wrong. if it won’t calibrat I would try to check it out

 

[FWB]

Does the rudder indicator move with the rudder?
If not or if haywire then the potentiometer may have seized and broken the pin which holds it.

 

[bigwow]

Does the rudder indicator move with the rudder?
If not or if haywire then the potentiometer may have seized and broken the pin which holds it.

Yes it moves with rudder, I can adjust that by shortening the rod, I can't understand why the reading has changed.

 

[FWB]

Yes it moves with rudder, I can adjust that by shortening the rod, I can't understand why the reading has changed.

If the ref unit is still correctly aligned on the outside then the potentiometer may have moved inside. There is a thread on how to repair it which I can post if that turns out to be the case.

 

[KompetentKrew]

Re-calibration of the compass I can go with, however the rudder indicator is a mechanical rod from the tiller to the unit, before I start messing about altering the length of the rod I just wondered if there could be any reason it could have gone 30 degree out just sitting there.

Resistor short.

The Raymarine M81105 rotary rudder reference transducer is basically a potentiometer / resistor, wired like this.

I think it's most likely a single-turn 10kΩ potentiometer restricted to a travel of about 60°.

You might test by shorting blue to red or green (I would use a < 1kΩ resistor just to be safe, say 500Ω) and see if it makes any difference, but probably best to follow this Raymarine support article in the first instance.