auto pilot quesion

[openhouse]

this might be a little lengthy so please be patient. i've owned a beneteau 321 (1999) for 5 years. i love the boat. it had an autopilot installed by the previous owner Raymarine ST4000+. it worked perfectly the first 3 years. the second part of last season and all of this season so far it has not been working properly. i've read the manual front to back and performed all the fixes that they mentioned. i spoke with someone recently and they told me that there might be something metallic too close to the fluxgate compass. fair enough, but my issue is that i can't find it. i've opened, i think, every hidden compartment, looked everywhere but i can't seem to find it. does anyone know of a few of the places that it might be hidden?

now, that issue aside.....if that's not my issue i guess i have a different problem. i'll explain as briefly as possible. the compass on the auto pilot will not stay on one heading. the compass is constantly displaying a new heading every 2-3 seconds and by a new heading i mean it will go from 321 to 145 to 90 to 80 to 90 to 220, etc i assume you get the picture. other than that it has always worked fine.

any ideas?

 

[Manureva]

the solution that always work for me is asking myself 2 question, 1 is what did i change since the problem ocured and 2 is wich is the stupidest thing that could cause the problem, like unpluged partialy, dirty terminal, bad battery, or simply my wife change where she put the tea pot. 90 % of the time , sitting down and answering those question helps

 

[DanM]

Openhouse,

I have the Raymarine S1 which came after the ST4000 so this may be apples and oranges but it certainly sounds like a flux gate compass problem. My S1 has a grey box where the brains are that the flux gate compass is wired into. If you have that sort of control head (I think Raymarine calls it the Core Pack) you could then trace the wires to the flux gate compass. From your description though I wouldn't guess that it is metal too near it, but that it has failed or has come disconnected partially or has a poor connection. If it were metal too near it I would expect that it's heading would just be off by some set amount, not vary in the way you describe.

Hopefully now, someone won't come along and tell us all that the ST4000 doesn't use a flux gate compass!

Good luck, let us know what you find.

DanM.

 

[JVB]

I would bet on a bad electric connection inside or outside the unit. It could be a stranded wire that is down to just a few broken strands making connection intermittently. Can you take the unit out and test it away from the boat ? Even better would be to swap the unit for another and see if that does or doesn't fix the problem. That would help to narrow down the location of the problem to "in the autopilot unit" or "in the working environment".

 

[openhouse]

that electrical connection idea sounds like a good possibility. i'll check out all the connections tomorrow and start another search for the compass. thanks for all your responses.

 

[mitiempo]

Flux gate compasses are usually mounted fairly low down and on or near the centerline of the boat. Popular locations are under a settee in the main cabin or under the dining table sometimes.

 

[kloudie1]

There has been some discussion here about the connectors on the back of the control head. The five fluxgate wires have very small spade connectors that can get loose. .. Locate these and make sure they are tight and make sure that the male part of the connector is in the female part and not between the female connector and the vinyl cover. While the wires are off, check as follows:

2.1 Functional test​

Disconnect the Fluxgate from the Autopilot and check continuity as follows:​

Cable colour Connector pin number Resistance​

Screen to blue 2/4 < 10 ohms
Red to green 3/5 < 5 ohms
Red to yellow 3/6 < 5 ohms​

Red to screen 3/2 Open circuit

 

[NotCook]

Similar issues

I've encountered a similar problem after several hours of operation. In my case, it may have been battery charge dropping too low. The other possibility is the laptop supportiing the navigation software sitting too close to the compass. You might consider these factors along with the others. I always like to recommend eliminating the easiest and cheapest options first.

Let us know if you figure it out.

 

[openhouse]

finally found my fluxgate compass. it was under the sink, accessible by the door to the trash bin, down close to the floor and near the center of the boat. now all i have to do is diagnose the problem. is it possible that the fluxgate compass is broken and needs to be replaced. i'm going to check all electrcal connections this weekend between the two and hope i find my problem. if everything seems to be kosher with the wiring would a more logical diagnosis be the auto pilot itself or the fluxgate compass? can just the compass be purchased and replaced or is it a much biger deal than that?

 

[Witzend]

Usually lots of metal in that location, IE pumps and such.

 

[higgs]

Call Ray Marine. Their tech support is very good.

 

[Ken Cross]

Don't put a meter on a flux gate

I doubt it's metal near your flux gate unless it's moving around. If you engage the autopilot in the slip and the wheel doesn't move it could be magnetic materials interfering. If it is erratic with the boat in a fixed position, the problem isn't magnetic materials.

Your problem sounds like corrosion as described earlier. I suggest you don't put an ohm meter near the flux gate wires. It's really easy to ruin the flux gate by magnetizing it. A simple ohm meter can do that if it puts out high enough current. (fortunately modern digital meters have pretty low current flow.)

I don't know if the ST4000 uses feedback from the wheel position or not. If so it also could be the culprit.

No matter what checking each connection for corrosion, contamination, or loose connections should fix 90% of the problems.

Ken

 

[kloudie1]

Quick Note, Ken.. that part of my note about measuring ohms is directly from the RayMarine service manual for the 4000.. Yes, ya have to use a sensitive meter..

 

[openhouse]

i can't thank you all enough. today i took apart my autopilot control panel and checked all the wiring connections. one of the wires was loose. i re-crimped it then went through all the other connections checking them also. after i put everything back together i took the boat out and it worked perfectly. i can't tell you how frustrated i was, i went from boston to martha's vineyard and back with no working auto pilot all by myself. about 24 hours of sailing time in 4 days and it was making me angrier as each hour passed. now all i have to do is get all the settings back the way they were before and i'll be a happy sailor again. thanks for all your help.

 

[Stu Jackson]

Congratulations. Like we say a lot: "If it's electrical check the connections first!"

 

[higgs]

Nothing like bouncing a problem off others to get a solution.