Raymarine ST 4000 steers hard to port

[Bill Asbury]

Owned my 2005 C34 seven years and Otto the autopilot always performed perfectly until earlier this season when he started steering hard to port every time.
Have not changed or added any other electronics in the cockpit or anyplace else on the boat, so am wondering if anyone can suggest a cause/fix.
Called Raymarine and left message for tech response some time ago but no response and found no help in the owners manual.

[Roc]

Hi Bill,
Did you check if you happened to place any metal object near the fluxgate compass?

[britinusa]

And...  Have you installed any new electronics recently - even if totally independent of the Raymarine Otto.

[Bobg]

sometimes water find its way behind the screen , happened to me , I removed the water, added a gasket, trouble went away.  Trouble went away that time anyway :)

[Dave Spencer]

Bill,
I have had very good luck with the Raymarine Technical Forum. Although Raymarine doesn't support the ST4000 any more, there is some great advice on the forum including some from Raymarine technical support people.  It's certainly worth a try. Phone calls to Raymarine are unlikely to be supported.

[Bill Asbury]

Thanks all for your prompt responses.
No metal objects installed near compass.
No new electronics installed.
Will check Otto for water incursion.
Will check Raymarine tech forum.
Kind regards.

[Craig Illman]

See this thread: http://c34.org/bbs/index.php/topic,9580.msg72287.html#msg72287  and/or also search on "autohelm repair"

[Stu Jackson]

Great link, thanks, Craig.

Here's another one, same suggestion, Dan is a good guy!

http://c34.org/bbs/index.php/topic,7129.0.html

[Jim Hardesty]

Bill,
You said that your st 4000 worked well.  I was never happy with mine, but I lived with it.  I changed to the Raymarine Evolution ev100.  Very happy with the new unit.  Before you spend a few hundred on repairing old electronics think about replacing.  It worked well for me.
Just my 2 cents.  Best of luck what ever you decide to do.
Jim

[Bill Asbury]

Thanks for all the responses and suggestions, guys!
Will do some checking and let you know what happens.
It's boat show time here in the Sailing Capital.

[Jim Hardesty]

Bill,
Thought of something when I was sailing today.  If you have a Rudder Position Sensor it may be broken or disconnected and your autopilot is trying to steer to a faulty input. 
Jim