Bl*%^+y Autohelm (6000 Course computer)

[BlueSkyNick]

Cut a very long story short, we've had a number of issues which I have addressed during the winter. This included taking the computer and the drive unit back to Raymarine so they could test them working together.

computer had new output FETs, drive unit had new clutch belt, bearings and stuff.

Put the whole thing back in, and original problem persists !! Arrgh.

Motoring along in flat sea - press Auto button - helm goes hard over to starboard, and boat goes round in a circle.

Rudder reference unit is working fine - at least it is showing the right position on the display. Fluxgate seems to be working fine, in that it is displaying the correct heading of the boat.

I am beginning to wonder if there is a hidden relay between the motor output of the computer and the drive unit. If so, it could be just applying full power on the output, regardless of the computer.

Is this likely?
Any other ideas what might be causing this?

 

[sarabande]

are there any DC electrical circuits near significant bits of the system ? Even ones which intermittently switch on/off, e.g. bilge pump ?

What were the original problems ?

 

[spannerman]

Had a similar problem once, it was the actuator wired back to front, so when the system detected the boat going off heading, it applied the actuator to correct the course but it was motoring the wrong way so it went even further off course and so applied even more correction the wrong way, so it ended up with the rudder hard over.
Try reversing the output connections to the rudder actuator / motor.

 

[prescott56]

just installed mine last week, and when first powered up and pressed auto the wheel went hard to port, it did say in the commisioning book to opposite wire the motor feed. i did this even though the colour coding was correct and now all works well.
But i would have thought raymarine woul dhave pointed you this way.
Good luck
Roy

 

[PembrokeshirePromise]

I had the same issue (S1) - after a bit of head scratching and reading the small print - reversing the motor cables worked for me too

 

[Richard10002]

[ QUOTE ]
I am beginning to wonder if there is a hidden relay between the motor output of the computer and the drive unit. If so, it could be just applying full power on the output, regardless of the computer.

Is this likely?
Any other ideas what might be causing this?

[/ QUOTE ]

Hi Nick,

very frustrating, to say the least.

I am 99.999% certain that there isnt a relay, or anything, between the computer and the motor on the Linear Drive.

When my FETS were blown, the drive went hard over one way. So the FETS may have blown again???

I am also reasonably sure that at the linear drive end of the system, I have connected red from the computer to black into the drive moter, and vive versa, so the other answers you have received make sense.

I've pm'd you with someone who may be able to help.

Cheers

Richard

 

[Danny]

If reversing the connections don't fix it it might be worth checking the wires in the cable from the computer to the drive motor. Check end to end continuity of each wire and also check for no shorts between wires. A simple multimeter should do the job. A problem here could account for the blown driver and wouldn't have been found by Raymarine unless you took the cable along with the rest of the kit.

 

[BlueSkyNick]

To all- thanks for the replies - since the original post we have spent time either eating or drinking and now keeping warm !! We are one of four boats on the Folly (up river from Cowes) pontoons, where I've seen over 100 in the past!

There is snow all over the decks, and the eberspacher is doing a great job

Back to the point, I will reverse the wires and see how we get on, but it does mean putting black to red and vice versa.

Will update here later this evening - frostbite permitting !

 

[BlueSkyNick]

Sorted at last, thank goodness !

wires reversed as suggested, out into the Solent, F5 on the beam 10kts SOG, hit the Auto button and kept on going - great relief. Then pressed Standby and Auto together, and steered the wind.

thanks again, to all.

Now onto the next job. /forums/images/graemlins/confused.gif

 

[Richard10002]

[ QUOTE ]
Sorted at last, thank goodness !

wires reversed as suggested, out into the Solent, F5 on the beam 10kts SOG, hit the Auto button and kept on going - great relief. Then pressed Standby and Auto together, and steered the wind.

thanks again, to all.

Now onto the next job. /forums/images/graemlins/confused.gif

[/ QUOTE ]

Dont forget to get some kind of grease/oil down the conduits. I'm sure stiffness down there was the cause of my FETS blowing!!