Autohelm ST 7000 all of sudden wont hold course...

[Jbingham]

hi all! hope everyones getting ready to welcome spring! we've been lucky enough to enjoy most of the winter down south on our boat but with the trip home to the new england area looming we have a new issue we need to trouble shoot, something not too easy when youre 1800 miles from your boat!

we have an older autohelm st7000 set up. worked like a charm all the way from newport to virgin gorda. worked great down there too until the last couple of days of my last trip there. it would operate perfectly right up to when you set the course (would ready properly on the control head unit etc) but then would just fall off course and the alarm would sound.

Im dealing with a few challenges. troubleshooting int he tropics aint easy. nor are finding parts.

if something is dead what would it be? control unit? and if so what is a swappable replacement? you dont need to upgrade all the components of the autopilot system i hope?!?!

[cabo_sailor]

As you say it could be the controller but I once had a similar problem and it turned out to be a bad fluxgate compass.



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[Jbingham]

Originally Posted by cabo_sailor

As you say it could be the controller but I once had a similar problem and it turned out to be a bad fluxgate compass.



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Do you know what the compatible and available replacements are? Thanks in advance! I may just buy each and send down to avoid bloated service charges trying to diagnose. :-/


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[phantomracer]

had a similar problem with my st7000. was a bad connection with the fluxgate.

the reading on the head unit reading accurate?

the actuator working correctly?

Could be a bad rudder sensor as well.

wind/speed working? mine worked better when the speedo was working.

we have a KVH heading sensor on our boat. works quite well

[phantomracer]

when I was troubleshooting my problem a while back, I bought another KVH compass. It is still new in box, sitting on the shelf.

If that is what your problem is , can make you a deal. Probably be more than getting a used autohelm heading sensor, but the kvh is pretty awesome just the same.

[sy_gilana]

Do the compass swing procedure, turning the boat in circles. If this fails, it suggests fluxgate is faulty.

[brazenarticle]

Missing any screwdrivers with a magnetic tip? Or a flashlight with a magnet mount?
My ST 4000 behaved similarly, after going crazy with it for a few days I remembered I lost a screwdriver behind a panel near the flux gate compass. Once I dug that out ( with great effort) all was fine..

[phantomracer]

unsure of the autohelm heading sensor (or other heading sensor),but the KVH is always in autocompensation mode. Only have to do slow circles once to calibrate it.

It has to be either the heading sensor, or rudder sensor. Its really the only 2 inputs (other than, perhaps, wind/speed)

If the heading on the display is accurate, I would tend to lean toward a rudder sensor.

[CLady]

Having you stowed something metal or magnetic next to/near the floxgate compass? That will do it.

[adlib2]

I have the ST7000 and ST7001 for control at the Helm and at the Nav Station below. Have worked fine for me since 2006 both on the Great Lakes and in the Caribbean. Only time I had instances of not holding course was when I damaged my rudder. Once repaired controls were fine.
If you're still in the BVI's then an overnight sail to St.Martin will bring you to Simpson's Bay Lagoon where there is a Raymarine repair and sales facility on the Dutch Side. Close to Island Water World and Budget Marine and no Tax.

[Bill_E]

The prior owner of my boat had an autopilot problem and it turned out that his son had stowed his toolbox in the locker right next to the fluxgate. Since hearing that story, I've made a point of using that space for non-magnetic stuff. A few years ago I had some problems with my Raymarine seatalk instruments. I went to the trouble to sign up on their website and entered all of the information I had. ( the PO was the one who purchased and installed allof the hardware.) Their blog with technicians was extremely useful. Here's the link to their technical community support forum. Raymarine Technical Forum I think you may have to sign up to get there but it's all free. Try searching around there. Good luck.

Bill

[Valmika]

Ditto on the fluxgate compass with mine. Mine however was I had set a large 4D battery on the wire leading to the computer from the compass. I guess it pinched the wire enough to make it a bit iffy. Once I cleared the wire all was well. If I were you before I ordered anything I would check all connections from components to the course computer.

[ka4wja]

j,
I thought I replied to this thread yesterday, but somehow it didn't post....oh well, here's the gist of what I wrote...


I'm assuming (along with the others here) that you have an older Autohelm / Raymarine belowdeck autopilot of either a type/model 100/150, 300/400 (or the newer S1, S2, S3 series, either with rate gyro or without), and the control head / display in your install is the ST-7000???
(all below is assuming that is correct..)

I understand the complications/frustrations associated with troubleshooting this problem from 1000's of miles away...it's what we do here all the time!

It initially sounds like a heading sensor / fluxgate issue, or a rudder position sensor issue....but without further detail, we are all guessing!
And, while I agree that "swinging" the compass is a good idea....you may want to look for a simpler cause to the problem first...


1) Look at the ST-7000 control head / display (or have someone you trust do it now, while you are on the phone with them, before you order any parts!!), with the autopilot On and in Standby....
Have then turn the wheel and make note of the rudder position indicated on the display....
If it is showing accurately and follows the actual rudder angle smoothly....then it is working at that specific moment....but we cannot be sure that it is always working...

Also, have them note the heading displayed....it should be very close to your main steering compass, of course!!
If the boat is on a mooring / at anchor, you're lucky...as you can have them just turn the boat in semi-circle, while watching the steering compass vs. the autopilot heading...
If there are wide variations, then you've found the proximate cause of your problem....(whether it is faulty, the wiring/connections are bad, or you have something metallic where it shouldn't be....still needs to be determined!)


2) Next is to have them look for metallic objects near the heading sensor / fluxgate compass...
Have them look for any new metallic objects (or electrical wiring / electronics) within a few feet of your heading sensor/fluxgate compass...
{True story: One of my brothers found a car of shaving cream on the floor of the aft head, and instead of putting in one of the head lockers, he stuffed it in UNDER one of the aft cabin lockers (never sure why!), and that placed it about 12" away from my heading sensor....and that metal can of shaving cream changed my heading by 20* - 40* depending on exact heading...
When I went looking for the problem, the first thing I went to was the heading sensor to look at its wiring / mounting....and as I was about to dismount it and "swing" it by hand, I saw that damn can of shaving cream, pulled the can out and threw it across the cabin....and all was now well with the world!!!}


3) If those simple tests/examinations show no issues, then have a look at the wiring / connections of all the autopilot wiring, specifically the heading sensor and rudder position sensor wiring....




4) If all of those show no issues, then proceed to swing the compass....
If you do not have anyone there that can perform this (which is a LOT to assume that any dockmaster would even attempt, let alone complete successfully), then I'd say buy a new heading sensor and wiring, and take that with you when you fly down to the boat...

The Raymarine heading sensors of today should work fine for you (but not sure what autopilot you actually have, so cannot be 100% certain), and they are only a few hundred dollars....and will fit in your pocket!

Originally Posted by Jbingham

we have an older autohelm st7000 set up. worked like a charm all the way from newport to virgin gorda. worked great down there too until the last couple of days of my last trip there. it would operate perfectly right up to when you set the course (would ready properly on the control head unit etc) but then would just fall off course and the alarm would sound.

if something is dead what would it be? control unit? and if so what is a swappable replacement? you dont need to upgrade all the components of the autopilot system i hope?!?!

5) Should you have another problem, which you'd need someone on-board to test/troubleshoot for, then you may in fact need other replacement parts....

In order of probable failure, some other parts that have failures:
-- autopilot wiring / connections (cheap)
-- rudder position sensor $
-- autopilot itself (corepak) $$$$
-- drive clutch $
-- drive $$$
-- control head $$


Not sure if I helped much....but 'til you provide more details, and/or get someone on-board to do some hands-on troubleshooting, that's about all I have...

Fair winds...

John

[Valmika]

Never mind my last post. I think it was the wire from the rudder sensor that caused the problem. There are test procedures on the Raymarine website for all the above. All you need is a multimeter. Ceck your connections first though.

[serannity]

We have an ST6100 with many miles and 13 years. On multiple occasions it has not held course. After factory recommended trouble-shooting and cleaning all other connections we found that the problem was the connection on the negative supply from the battery.