We have the wheel-mounted ST4000 autopilot, which has recently been invaded by electronic gremlins. Of late, I've noticed that sometimes magnetic course readings on the display unit are consistently and significantly off (i.e. 20 or 30 degrees) from the data on our compass and GPS (which doesn't make any difference as a practical matter, as long as its holding a steady course), but at other times the readings are going all over the place (which results in corresponding craziness with the wheel!).
This was not happening before, and there has been no change in the installation. The fluxgate compass is mounted under the cabin sole to the left and forward of the bilge area.
Anyone had this problem in the past, and if so, were you able to correct it, and how? (The manual doesn't describe this problem, nor have I found this in prior threads -- although another thread indicated that it may have been a subject on the old forum, which I can't find)
Matthew Chachère
s/v ¡Que Chévere!
(Formerly 1985 C36 MKI #466 tall rig fin keel M25)
2006 Catalina Morgan 440 #30.
Homeported in eastern Long Island, NY
It is most likely a connector. Sequitur's blog post shows evidence of this: scroll down for photos - [url]http://www.sailblogs.com/member/sequitur/?xjMsgID=229889[/url]
All they did was sail around Cape Horn!:)
Stu Jackson, C34IA Secretary, C34 #224, 1986, SR/FK, M25 engine, Rocna 10 (22#)
[QUOTE=stu jackson c34;14196]It is most likely a connector. [/url]
[/QUOTE]
Hmm.. I've thought of this. I may just remove, clean, and reinstall connectors and see what happens.
Matthew Chachère
s/v ¡Que Chévere!
(Formerly 1985 C36 MKI #466 tall rig fin keel M25)
2006 Catalina Morgan 440 #30.
Homeported in eastern Long Island, NY
You may need to swing your compass. In other words every now and the take the boat out and motor in circles 3 or 4 tight ones. port and starboard turns at a slow speed. If you have an Iphone check the compass app and it almost always tells you to turn the phone in a figure eight to reset, its the same with any type of compass
Mark Middleton
S/V Lunacy
SW Michigan
2002 C36 MK II TR WK M35B
I hate to tell you that I had all the same problems and symptoms on my ST 4000 that you have. Went through all the remedies like, recalibrating, using the the Catalina cocktail, calling Raymarine for suggestions and potential rebuilding of the unit. All to no avail. I finally determined the only solution was to replace. Got a rebuilt S-1 unit from Raymarine for 2/3rds of the retail price. This was the older "rudder sensor" type, since done away with, that I installed, and it has worked like it was designed to ever since, @ 4-5 years, knock on wood! The old forums had many discussions of the 4000 unit and all it's problems. The conclusion was that it was a piece of junk.
Bill Taylor
Heel'n Good #1612
Washington, NC
While on a drearily long motorsail yesterday, I decided to RTFM ("read the friendly [or your choice of adjective] manual") for the ST4000, and was about to try recalibrating the unit when I came upon a sentence that said something like "if you need to offset the calibration by more than 15 degrees, you may need to think about relocating the fluxgate compass". It suddenly dawned on me that my recent addition of a second, backup bilge pump, close to the fluxgate, might be the problem. Took a hand compass to check out the impact of the pump, and it was not insignificant. Will remove the pump temporarily next weekend and see if that is the cure.
Matthew Chachère
s/v ¡Que Chévere!
(Formerly 1985 C36 MKI #466 tall rig fin keel M25)
2006 Catalina Morgan 440 #30.
Homeported in eastern Long Island, NY
Bravo, Matthew. It's a step in the right direction. Good troubleshooting. Let's hope it turns out to be the problem.
Larry Brandt
S/V High Flight #2109
Pacific Northwest, PDX-based
2002 C-36 mkII SR/FK M35B