autohelm st4000 problems

woodzy

.
Sep 21, 2014
81
Catalina 28 Oceanside Ca..
My autohelm st4000 has always worked. Now its started to read about 100 deg. different than what my gps reads and when I set it, it holds course for a short time then goes crazy steering back and forth 80deg. to 100 deg. starboard to port or port to starboard or to full lock and hold it. Any suggestions.
 
Jan 7, 2011
4,727
Oday 322 East Chicago, IN
My AP went crazy once (doing all sorts Crazy Ivan’s).

I swung the compass (a few circles of the boat) and that fixed whatever was causing it.

Greg
 
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Oct 22, 2014
20,995
CAL 35 Cruiser #21 moored EVERETT WA
Have you added a magnet or iron based metal near where your fluxgate compass is located? i.e a speaker?

Occasionally you need to recommission your AP by going through the set up function. As Greg stated he re commissioned the Fluxgate compass. Telling it "Hey guy... You are here now get it straight!"

The new systems from RayMarine are doing that constantly but even they can get fooled and need a circle to adjust the calibration.
 
Dec 28, 2015
1,837
Laser, Hunter H30 Cherubini Tacoma
Mine would work then not work. I found the ribbon cable that connected the compass to the circuit board fractured. New compass was $140. Works great now.
 
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RoyS

.
Jun 3, 2012
1,739
Hunter 33 Steamboat Wharf, Hull, MA
I believe your answers are above. I have experienced both issues described above. Once our waste basket contained a pringles tube with a metal bottom that rested against our fluxgate compass. That caused the boat image on the gps screen to be sideways. Another time I moved the fluxgate compass to the opposite side of the cabinet that it resides in and my compass readings were 180 degrees off. Did the circle exercise and all was well again.
 

woodzy

.
Sep 21, 2014
81
Catalina 28 Oceanside Ca..
So I don't have to go looking for it. Does any one have any idea where fluxgate compass is? I have a 1994 Catalina 28 #355 Hennis Vind
 
Oct 22, 2014
20,995
CAL 35 Cruiser #21 moored EVERETT WA
So I don't have to go looking for it.
Oh.. that is half the fun. Who knows who put the compass in on a 1994 boat. And who knows if it has been moved by a previous owner.

But the easy way is follow the wire from the Computer back to the compass. If by chance you choose the wrong wire it will lead you to the Wheel motor or the battery.

And there is always the possibility that you find a hidden pot of gold...
 
Oct 26, 2010
1,883
Hunter 40.5 Beaufort, SC
Oh.. that is half the fun. .

And there is always the possibility that you find a hidden pot of gold...
Did that and found a perfectly good 3 blade fixed prop! Sold it to someone here on the forum and pocketed a nice piece of free change. Also found a batten tool.

Most likely the fluxgate compass for a ST4000 looks like a fat hockey puck (black). You should take a little time and open every accessible hatch/opening/cubby and anything else where something can be anyway even if you find it right off the bat. You will know about your boat that way and might even be able to detect some pending problem that goes unnoticed otherwise. Its a good way to kill time one afternoon anyway.
 
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Jan 7, 2011
4,727
Oday 322 East Chicago, IN
Found mine in my bilge! I guess from a “get it low and in the middle of the boat”, this is a good spot.9F1EDD03-5FF6-4624-9AAC-E8CD06F1E3FE.jpeg

Good luck with the hunt ;-)

Greg
 
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Aug 21, 2019
156
Catalina 315 18 Grosse Pointe Park, MI
Sometimes the controller gets 180 degrees out of sync. This happened to me about a year ago and I had to do a reset and go through the setup again. After that, it worked fine again. I think the cause of it was that my Garmin GPS was contending with my Raymarine EV1 sensor core on the NMEA 2000 network about the what the compass heading was. I ended up getting rid of the Garmin.
 

woodzy

.
Sep 21, 2014
81
Catalina 28 Oceanside Ca..
Well folks, Before we went out sat. sharp 360s both ways inside the harbor and went out. Sailed for 6 hrs all different directions almost always at about 5knots mostly on autopilot and not a hiccup so that swinging must have fixed it thanks everyone
 
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Jan 7, 2011
4,727
Oday 322 East Chicago, IN
Well folks, Before we went out sat. sharp 360s both ways inside the harbor and went out. Sailed for 6 hrs all different directions almost always at about 5knots mostly on autopilot and not a hiccup so that swinging must have fixed it thanks everyone
Good to hear.

Greg
 
May 1, 2011
4,192
Pearson 37 Lusby MD
not a hiccup
That's great to hear! I had a crazy Ivan event several years ago when I placed a bag of Granny Smith apples in the drawer just above my fluxgate compass.
 
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Oct 22, 2014
20,995
CAL 35 Cruiser #21 moored EVERETT WA
bag of Granny Smith apples in the drawer just above my fluxgate compass.
Never knew a Fluxgate Compass was partial to Apples. Maybe it is the old saying... Apple a day keeps the compass away...