[C320-list] Issues with ST4000+ Autopilot

[Ferris Wills]

John,

I see a similar behavior: when I first engage the ap, it will occasionally veer to port immediately. This happens maybe one in twenty engagements. Otherwise it works as expected. I simply disengage and reengage and that always works.

When I first bought Argo (#505) two years ago, the ap was not working - I disassembled the wheel mechanism, replaced the belt and cleaned everything . I also rewired the electrical leads to the motor as I found a bad connection there. Finished by recalibrating as per instructions in the manual. 

The weird veering behavior is kinda recent, so I should probably check my motor connections again - that seems to be a weak point in the design. I don’t have a rudder sensor. Let me know if you get to the bottom of it!

Thx,
Ferris
Argo #505

Typos by iPhone

> On Jul 16, 2024, at 6:10 PM, John Stetson via C320-list <c320-list at lists.catalina320.com> wrote:
> 
> Dennis,
> Thanks for the input, particularly from your hull number!  I have checked
> the rudder position sensor and it seems to be working fine.  In fact, the
> whole system seems to be functioning as it should.  I am thinking that the
> intermittent nature of the issue is a wiring problem.  Very frustrating to
> not know when it is reliable and when it is not.
> 
> 
> John Stetson
> Morning Star...Again
> Hull 578
> 1999
> 
>> On Mon, Jul 15, 2024 at 4:56 AM Dennis Cookson via C320-list <
>> c320-list at lists.catalina320.com> wrote:
>> 
>> John, check that the ST4000 controller is showing the correct position of
>> the rudder at the bottom of the display, adjusting as you turn the wheel.
>> If not, check the wiring from the rudder reference unit (position
>> indicator) to the SmartPilot unit in the aft lazarette.
>> 
>> Your vessel was built at the same time as ours and we likely have the same
>> system!  I am currently relocating my rudder reference device as it was
>> never installed properly and only worked in light winds.
>> 
>> Dennis Cookson
>> ‘Catalina’ 0577
>> 
>> 
>> 
>>> On 14 Jul 2024, at 18:32, John Stetson via C320-list <
>> c320-list at lists.catalina320.com> wrote:
>>> 
>>> Our Raymarine ST4000+ Autopilot system is original, installed in 1999.
>>> When activating the AUTO mode, the helm goes hard to port.  We have
>>> verified the Dealer settings and recalibrated, including successfully
>>> turning the boat to swing the compass.  Intermittently, the autopilot
>> will
>>> work correctly and then, unpredictably, initiate the same turn on its
>> own.
>>> We have confirmed that there are no ferrous metals within 0.8 m of the
>>> fluxgate compass.  Would appreciate any words of wisdom short of
>> upgrading
>>> to the Evolution EV-100 Wheel Sail Autopilot.
>>> 
>>> 
>>> John Stetson
>>> Morning Star...Again
>>> Hull 578
>>> 1999
>> 
>>