Raymarine Autopilot ST6001+ Drivestop Error Message

[manlyp]

Advice required please? The auto-helm on my Jeanneau 45.2 has given great service over the years, it's 10 years old, but recently it's developed an intermittent fault. It comes up with the message 'Drivestop Error' and the alarm sounds even though there is no weather load on the helm and the rudder is in the central position. I've checked the sensor on the rudder quadrant and it looks fine to me. The drive-stop position sensor is connected to a Type 400G course computer. When you reset the auto-pilot by going from Auto to Standby and back to Auto again it's fine for a while and then it happens again!

 

[concentrik]

I think I remember correctly, that the unit is expecting to see feedback from the rudder angle sensor (RAS) - pretty much straight away when the ram is commanded to move. "DrivestopError" is just what it says - it thinks that the drive (ram) is not moving. It thinks this because it's not getting any (or incorrect) info from the rudder angle sender. This can be because there really isn't any drive or because the RAS or its associated wiring is faulty.

I don't know what your head unit displays - do you have a crescent scale which indicates rudder angle? If so does this change correctly when you swing the helm? The 'intermittant' aspect is the main prob of course. You need to be able to provoke the fault at will to locate, repair and test. Look carefully at the head unit to see what it displays before the fault occurs (hard, I know).

 

[pampas]

Have found the same on mine, Put it down to the operating unit taking to much load. In my circumstance its because I use a highly modified tiller motor and ram which strickly speaking is not 100% compatable, but works of if the sea conditions are slight to moderate, so perhaps you drive unit is intermittently overloaded?

 

[emandvee44]

I have exactly the same problem, with the same autopilot and course computer. Slight variation in my case, as when the fault occurs, going to standby and back to auto does not clear it immediately. The fault may persist for several minutes and occurs in even low load conditions.
I did contact Lewmar/Whitlock who suggested that it was a clutch problem and recommended sending the motor/clutch unit to them for service/re-adjustment.
Haven't got round to it yet

Cheers,

Michael.

 

[manlyp]

The display is showing the correct rudder anchor. I now suspect the motor brushes - they maybe worn or dirty - as they've had a lot of use. I'm going to strip-down the ram and have a look.

 

[rotrax]

The display is showing the correct rudder anchor. I now suspect the motor brushes - they maybe worn or dirty - as they've had a lot of use. I'm going to strip-down the ram and have a look.

I think you are on the right track. Suffered a similar problen two years ago. When I stripped the little motor it had a dirty commutator-the cause was clear as the brushes had plenty of length left but the springs that push them into contact were fouling the brush boxes. A bit of tweaking with some small long nose pliers and a clean up of the com. and all was well. As a footnote, Raymarine were not helpfull at all when I called their technical helpline. The Raymarine dealer in Plymouth pointed me in the right direction-thank you!

 

[westernman]

This error message occurs when the course computer is trying to move the rudder, but it thinks it is not moving. This could be because the rudder indicator gives no indication of any movement and (I think), it cannot detect any change of course from the compass/gyro input.

You already said that it looks like the rudder indicator is working. In which case probably the electric motor (in my case drives a hydraulic pump, but could be mechanical link), is not working.

You can easily check by disconnecting the motor connections from the course computer and connecting to ground and +12V to see if the anything happens. The motor should of course easily move the rudder from one lock to the other.

In my case the motor was badly rusted and nothing was happening. As I was in a hurry at the beginning of a two weeks cruise (which could not be moved later) I ended up getting a whole new motor and hyraulic pump installed (in a slightly better location out of any water which might collect).

With time, the motor could probably have been separated from the pump (very badly rusted so would have been a significant challenge to do without stripping threads) and repaired by a specialist. My cruise with family and friends was more valuable........

 

[manlyp]

Problem with Autohelm ST6001 now solved.

I took the drive unit apart and disassembled the Fracmo stepping motor. It was filthy inside but surprisingly the brushes were in pretty good condition despite having had nearly 1800 hours of use. I resurfaced the commutator with 440 grade wet and dry, cleaned everything with turps impregnated kitchen roll and reassembled. It's now just done 8 hours without a murmur off the East coast of Spain. I will be buying a spare set of brushes when I get home!