autopilot woes

[gunter meyer]

I seem to be snakebit when it comes to putting anautopilot on my H27. First I installed a WP30 only tofind out that it does not fit the small wheel of theH27. Now I have an ST4000 and a new problem.The compass reading on my control head oscillatesup and down through as much as 7 degrees eitherway. This happens even with the boat tied up inquiet water, no shore power on board, all circuitsoff except the autopilot circuit. It happens regardless of where the compass is placed, on the cabin floor or on top of the cabin where the compass isnot near batteries, engine, radio or speakers. Voltage to the control head is steady, cables areorginal and not spliced, and the compass resistancesmeet specs (like 5.4 ohms whem specs say < 5).Raymarine says that is ok. Raymarine also tells me the compass needs to be linearized every time I move it. I did that after the first installation, but to no effect. Besides, I am not complaining about deviation but about a dynamic behavior when everything should be steady state. Raymarine tells me do this, do that but do not seem tohave an explanation. Has anybody had a similar problem? Any ideas and advice will be appreciated.

 

[Jim Hague]

That's odd

Gunter - The ST4000 on my 81 H30 is very steady under the circumstances you described.Sorry, I have no idea what is causing this. If we were nearby we could swap control heads and at least isolate the problem to compass, control head, or boat. Good luck.

 

[Gene B. s/v Paradigm]

Check voltage

You'd be surprised how often seemingly good connections and wiring turn out to have a voltage drop or intermittent break in them. Borrow a good voltmeter, and check the voltage at the control head. See if the fluctuations in the bearing are accompanied by fluctuating or low voltage at the head. In my experience in the electronics field, the top three causes of problems are connections, connections, and connections, in that order!