Raymarine st4000+ autopilot problems

Jun 17, 2012
165
Hunter 356 Mackinaw City, MI
my boat is a Hunter 2002 356. The auto pilot has been working pretty good in light wind and calmer waters for years. However all of a sudden it just wanders even with no sails and flat water. In addition I notice that the compass reading does not agree with my mechanical liquid filled compass. The Raymarine has always been a couple degrees off but now it’s way off always. I always set the rudder gain to 1 and the response to 2. So I called Raymarine. Of course they no longer service this unit and no parts available. The tech believes it’s the fluxgate compass. He provided voltage readings to test with. I have not done that -yet. But just in case I searched for a fluxgate compass for my model on eBay with no luck. If anyone can help me here that would be so appreciated.
‘I need first to know where the fluxgate compass is located on my 2002 356. And I need to know if the st4000+ has a reset. Anyone has experienced this problem please share what you did to solve it.
 
Jan 5, 2021
92
Hunter 41 DS Saint Petersburg
I have an ST7001 and have the same problem with it. Raymarine needs to know which ACU is installed. I haven't found that controller yet. My Fluxgate compass is amidship, under the sole, tucked up and away. I had to stick my head in the bilge area and look up. A Leprechaun must have installed it. There is no set place for it to be. Just wherever the installer decided at that moment. Look low and center. Good luck.
 
Jan 7, 2011
2,919
Oday 322 East Chicago, IN
Sometimes you have to “swing the compass”…run the boat in a few circles to recalibrate.

my boat would do a ”Crazy Ivan”, and after I swung the compass, it was better.


Greg
 
Jun 17, 2012
165
Hunter 356 Mackinaw City, MI
Thank you tally ho. Could you explain how you swing the compass. Is the auto pilot on? Is it engaged? How many circles? circles in bot directions? How many circles? Thanks for your help.
 
Jan 7, 2011
2,919
Oday 322 East Chicago, IN
Thank you tally ho. Could you explain how you swing the compass. Is the auto pilot on? Is it engaged? How many circles? circles in bot directions? How many circles? Thanks for your help.
Nope…just have the system on so the flux gate compass is active, and drive the boat in a few circles…I think 3 is sufficient and it only has to be in one direction.

Another thought is to make sure you haven’t put some metal near the flux gate compass. Mine is located in my bilge, and one time my bag of tools was placed on the cabin sole, near the bilge…and the AP was acting erratic…I moved the tool bag, and all was well.

Good luck.

Greg
 
Apr 8, 2011
468
Hunter 36 Deale, MD
The manual for the ST4000 explains the process to swing and calibrate it, and that's available online. You'll need that. Let us know if you can't find it. As for where the fluxgate is located, I have a 2009 H36, which is a sister to your 356, and the fluxgate compass is located in the forward cabin, port hanging locker, under the floor of it. Not too hard to get to, probably just a few screws and voila. I'd also check to see if perhaps you stowed anything big and metallic near the fluxgate compass, which could be causing you problems. It could even be in the port locker under the settee in the main cabin.

Good luck. Let us know how it goes.