Autohelm ST4000 Plus problems
[Did the best I could with other threads on AH 4000 and don't see answers to my issues - thus this post]. My setup is an 'Autohelm ST4000 Plus' on a bank of 4 AH instruments - depth, speed, wind, and the autopilot. It's a wheel lock system. The lock seems to work fine, and from other posts I don't believe the instruments are interconnected, as the light only works on one of them and doesn't affect the others, but that's just background context. When I bought the boat a year ago the autopilot worked on a sea trial.
In priority order the issues are:
1. Can't steer via autopilot even with the engine running. It now veers all over the place (well, I can't wait long enough to find out what it might EVENTUALLY do). Initially it had a course that was way off. I tried the calibration procedure on SF Bay and did 6 slow circles under 2kts, but it never registered any result. When I stopped calibrating it defaulted to zero deviation. I entered the correct compass course at some point, but it just gets confused. Any idea what could be wrong? or what further research I need to do to pinpoint the issue?
2. Never could autopilot steer when under sail power for very long because I'd get a "low battery" warning and/or a flashing AH4000 message. As far as I can tell the batteries were NOT low. If I started the engine I USED to be able to use autopilot for hours. (which is most useful singlehanded)
3. The compass course is off and won't respond to deviation input. This is low priority because I know where I'm going and have GPS and compass, so I don't need this.
What I need is for the autopilot to work again at least under engine power, and hold a straight course when I set it (even if it's displaying the wrong compass reading), and then be able to vary that course by 1 or 10* on request. I don't need the tacking 90* feature.
I know there is a lot newer/better technology out there, but I'd much prefer to invest my budget in sails and speed, rather than have to upgrade this device.
Thanks for your insight.