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!
Quote:
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?!?!
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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