Raymarine ST6001 AutoHelm Controller keeps switching from Auto to Standby

[scr0che]

I've trawled everywhere for an answer but to no avail! It's very old, has been working perfectly last 8 years I've had the boat, but now it seems to almost continually switch from Auto to Standby. Does anyone have any ideas? I've redone all the electrical connections and cleaned etc.

 

[peteK]

It's usually a poor connection but you say you have checked .

 

[scr0che]

It's usually a poor connection but you say you have checked .

Yes, I took the unit out, it has 2x 3 pin seatalk sockets, put some contact spray in there, then re-crimped each of the thin 3 core wires. This is all back of the unit.

Is there anywhere else I should look?

 

[PaulRainbow]

Usually, when switching back to standby there will be an alarm and an error message. Bad connections are not confined to the plugs on the back of the controller, you need to check all of the components. Another common reason for switching to standby is a compass error, check there is nothing interfering with the heading sensor.

 

[scr0che]

Usually, when switching back to standby there will be an alarm and an error message. Bad connections are not confined to the plugs on the back of the controller, you need to check all of the components. Another common reason for switching to standby is a compass error, check there is nothing interfering with the heading sensor.

No alarm or error message, it just flicks back to standby. I'll trace the cables back and check at control panel and computer box. Where would I expect those sea talk cables to go to?

 

[pandos]

Usually, when switching back to standby there will be an alarm and an error message. Bad connections are not confined to the plugs on the back of the controller, you need to check all of the components. Another common reason for switching to standby is a compass error, check there is nothing interfering with the heading sensor.

You can check your compass by testing the impedance between the individual wires.

Mine was faulty whilst looking perfect, it was causing the auto-pilot to misbehave.

This would be one componet that you can eliminate

Be wary....Two of my connections broke whilst I was trying to remove the thin wires.
Fluxgate Compass Test

 

[PaulRainbow]

No alarm or error message, it just flicks back to standby. I'll trace the cables back and check at control panel and computer box. Where would I expect those sea talk cables to go to?

The wires could go virtually anywhere.

 

[lawrence_craig]

Mine did something like this. Sounds like a power or connection issue. Have you gone over all connections? Another would be to try alternative cables.
The only other possibility would be a fault in anything that controls the autopilot (eg. Plotter) but doubt this would be the case

 

[Blueboatman]

Does the control head audible beep sound feebler?
Does it disconnect still if you start the engine and rev it to put more volts through the system ( seriously ) ?
(Both indicate poor connections /higher resistance somewhere .)

 

[LadyInBed]

Do you have the ST6000/7000 Service manual?

 

[NickRobinson]

Does yours drop out when not driving the steering?
Mine (not the one I bought from Paul-) would drop out when it tried to steer one way, OK the other. I came to the concusion a mosfet had gone bad.

 

[Beelzebub]

Do you have a range of Seatalk instruments? A problem such as a bit of water ingress in one of these can cause problems elsewhere on the Seatalk bus, even if the instrument is apparently working OK.

The solution here is to take each instrument out of the Seatalk chain, one by one until the offending instrument is discovered. It's not a common occurrence but I have seen this happen on two different boats.

 

[PaulRainbow]

Do you have a range of Seatalk instruments? A problem such as a bit of water ingress in one of these can cause problems elsewhere on the Seatalk bus, even if the instrument is apparently working OK.

The solution here is to take each instrument out of the Seatalk chain, one by one until the offending instrument is discovered. It's not a common occurrence but I have seen this happen on two different boats.

I had exactly this two weeks ago on a customers boat. An issue somewhere on the Seatalk network caused the AP to stop working, whilst everything else seemed to work OK. Disconnecting the AP from Seatalk stopped the problem.

 

[scr0che]

Ok, I've spent the day on this and these are my findings:

1) Nothing metallic near the fluxgate compass - it's under the floor midships, and I've not put anything new near it for years, just cartons.
2) Checked all connections, replaced dodgy looking ones, and clean with contact cleaner. 12.5v at the computer more or less.
3) I tested the impedance on the fluxgate compass wires and I think it's not working correctly, according to the article posted by pandos :
red/green 0.59
red/yellow 0.59
green/yellow 9.00 (the article said screen/yellow, assume typo)
all other colors 1
silver wire, all 1 except silver/blue 8.8
4) The control unit is connect to seatalk, I traced the wires to a block with several. The wires from the device are crimped to a drop cable with individual cables exposed. It all looked good, I'm able to turn the pilot to standby/auto from the plotter, but not set a course as it's too old.
5) Audible beep on control unit is there as normal, no fluctuations, no difference if engine rev'd
6) It never drops out when steering pt or stbd, both directions work fine when the auto is engaged

So,
1) I will replace the compass for a start
2) I can also try disconnecting from the seatalk backbone if the issue persists
3) I'm going to try the 360 degree test tomorrow - to see the angle on the control unit changing according to speed and rate of turn - although the compass looks like it has failed
4) I'll also try during the day when the sun is out filling my batteries with solar, and also in the night with no solar. I'll also test with engine on/off to see if voltage drop is an issue, but I have 12.5v with solar off (breaker) and no engine.

Thanks all for the ideas, will report back once I have more results!

 

[James_Calvert]

Doubt this will help your particular problem, but I had a similar basic symptom: autopilot dropping out from auto to standby for no apparent reason.

Eventually traced it to weight (mine) going onto the top companionway step.

This ever so slightly deflected the ply panel above into which the switch/fuse panel was mounted and opened up a dry joint there, in the supply to the autopilot.

So the autopilot turned off when the power was interrupted when I stepped on the step, and turned on again, defaulting to standby, when I stepped off the step and the dry joint regained electrical contact.

 

[rotrax]

With our previous boat, an Island Packet 350, when sailing for long periods at night with the Electronics, Nav Lamps and Auto Pilot going we had a similar issue. Sometimes the complete display would go out, plotter and instruments.

It never occured if we were motoring or motorsailing.

I put 2 and 2 together, low voltage. Started the donk up, problem solved.

Probably no help, but you never know!

PS - After cleaning and rectifying stuck and dirty brushes in the small electric motor that worked the mechanical ram it never re-occured even when sailing for long periods at night.

 

[scr0che]

New fluxgate didnt work, readings still not looking great. So, bit the bullet and installed a new EVO and it works like a dream, not cheap though....