Raymarine C90W Chart Plotter problems

[Alaska JD]

I made this same post on a different thread yesterday and although it had a number of views there were no opinions or potential fixes suggested. I'm posting it again today with a different title hoping for some input.

Recently I bought a boat with a Raymarine C90 W chart plotter. I worked flawlessly for 1500 miles. Then, shortly after leaving an anchorage I noticed that it was showing me sailing backwards and the autopilot was showing a heading that was the reciprocal of what I was on. Additionally the tide current vector (blue arrow) was at it's largest size even though we were at slack tide. I reset the display to factory settings hoping for a miracle to no avail. The COG is giving the correct information. Does anyone know what the heck happened and how to fix it??

Thank you in advance for any productive ideas about how to resolve this without spending lots of boat bucks.

[Badsanta]

Try the raymarine technical forum. They answer pretty fast.

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[Alaska JD]

"Try the raymarine technical forum. They answer pretty fast."

Thank you very much - I'll give that a try!

[transmitterdan]

Originally Posted by Alaska JD

Recently I bought a boat with a Raymarine C90 W chart plotter. I worked flawlessly for 1500 miles. Then, shortly after leaving an anchorage I noticed that it was showing me sailing backwards and the autopilot was showing a heading that was the reciprocal of what I was on. Additionally the tide current vector (blue arrow) was at it's largest size even though we were at slack tide. I reset the display to factory settings hoping for a miracle to no avail. The COG is giving the correct information. Does anyone know what the heck happened and how to fix it??

It sounds like the autopilot computer has lost the flux gate compass calibration. This almost certainly has nothing to do with the C90W. It is just responding to the messages coming from the autopilot course computer. Look in the manual of the course computer and see how to recalibrate the flux gate compass. It involves driving the boat in circles typically.

It is also possible that the compass declination setting in the C90W has been changed but that is unlikely. Typically this setting will be set to the automatic feature and it then gets the declination from the GPS.

There may be some kind of memory failure of the autopilot but sometimes in rare circumstances the calibration data is simply lost. Did anything happen such as some kind of electronic disturbing event such as lightning or some DC electrical event?

[Alaska JD]

"It sounds like the autopilot computer has lost the flux gate compass calibration. This almost certainly has nothing to do with the C90W. It is just responding to the messages coming from the autopilot course computer. Look in the manual of the course computer and see how to recalibrate the flux gate compass. It involves driving the boat in circles typically.

It is also possible that the compass declination setting in the C90W has been changed but that is unlikely. Typically this setting will be set to the automatic feature and it then gets the declination from the GPS.

There may be some kind of memory failure of the autopilot but sometimes in rare circumstances the calibration data is simply lost. Did anything happen such as some kind of electronic disturbing event such as lightning or some DC electrical event?"

Transmitter Dan - Thank you so much for your response. The PO told me that he had the flux gate compass replaced last year when the autopilot would suddenly head the boat on a reciprocal heading. That seemed to fix the problem but I did notice the auto pilot "dropping off line" several times while ferrying the boat to Alaska. I didn't think much of it but possibly it was telling me of a coming problem. The auto pilot will follow a heading, but it's the reciprocal of where it's actually going. I really appreciate that the problem is not likely to the the C90W. I will find the documentation about re-calibrating the flux gate compass and follow that procedure. I noticed when I was trying to figure the problem out on the display, the compass correction values were missing and there was no way to manually enter corrections if I had them.

There were no electrical storms at any time since getting the boat and I'm not aware of any electrical anomalies or events on the boat.

It will be a couple of weeks before I'll be on the boat again but I'll let you know how things turn out. Thanks again for your response.

John

[smac999]

the heading (and boat direction on the screen) is coming from your autopilot. and has nothing to do with the screen. which pilot do you have? it may need to be reswung. or maybe the pilot compass has gone bad. or maybe it was just never re calibrated with the last owner changed it.

[ColinIOM]

Hi, I never understand why people do not go direct to the manufactures for answers to technical questions unless they have gone out of business.
I don't know the answer to your issue but I would start by asking Raymarine here Raymarine Marine Electronics
Best of luck,
Colin

[ColinIOM]

Again, sorry, but people that do not absolutely “Know” the answer, just confuse things with their own ideas. So should not post. (In my opinion)
A lot of people just watch and read posts with a view to learning and that’s how it should be, just allow the experts to post and stop guessing please.
I own a C80 plotter (which I am guessing) works similarly to the C90 and the plotter works just fine with NO Autopilot attached. So the information to the plotter does NOT come from the autopilot.
I could have some guesses too but I will not. Please just email Raymarine and I am sure they will help, then post their reply so we can all learn.
All the best
Colin

[smac999]

with no pilot it will use COG to align the boat on the screen. and the boat will be fine while moving and useless when not moving. if you add a pilot it will use heading to align the boat. COG and heading are 2 different things coming from 2 different places. COG comes from a GPS and heading comes from a heading sensor, which is attached to the pilot. heading will work at all speeds.


he can probably set it to use COG for alignment. which will aim it correct on the screen while moving. but that doesn't fix his autopilot. and if heading is available. then it should be used on the plotter for aiming because it's better then COG.


I don't know about the tides. check your time and time offset. maybe the plotter thinks your time is wrong. and therefore giving wrong tides.

[transmitterdan]

Originally Posted by ColinIOM

Again, sorry, but people that do not absolutely “Know” the answer, just confuse things with their own ideas. So should not post. (In my opinion)
A lot of people just watch and read posts with a view to learning and that’s how it should be, just allow the experts to post and stop guessing please.
I own a C80 plotter (which I am guessing) works similarly to the C90 and the plotter works just fine with NO Autopilot attached. So the information to the plotter does NOT come from the autopilot.
I could have some guesses too but I will not. Please just email Raymarine and I am sure they will help, then post their reply so we can all learn.
All the best
Colin

Colin,

Most of the time there is not enough information available to "know without a doubt" what the problem is. That's the case here. In such a situation we may not know for sure what the problem is but maybe we can help by saying what it is not.

In a typical Raymarine system the magnetic heading information comes from the course computer. The simple reason is that the course computer needs to know the heading at all times in order to steer. It does not need a multifunction display to steer. So Raymarine engineers quite logically designed the system such that the compass connects to the course computer which in turn sends the heading information to various displays. The poster has said the wrong heading was displayed by the autopilot and the C90. That almost certainly proves the problem is not in the C90.

[keepondancin]

I had a similar situation with my Raymarine system, with a e90. I mistakenly left the dock in declining weather. I could get no heading. I thought about it and wondered if it was the flux gate compass. Because of bad weather, I couldn't swing the boat to recalibrate it. I dismounted the compass, and swung it manually as described in the manual, 2 minutes if i remember correctly. Next morning, everything was good. I would suspect that could be your problem. As to why it happened, anybody's guess. Maybe you could keep us posted.

[Bacchanal]

I had a similar issue and it was the fluxgate compass. After a lot of time spent, some by a tech insisting that I send my autopilot and C90W back to Raymarine, I discovered it was caused by me putting my life raft in the main cabin right on top of where the fluxgate compass was located under the floorboards. The iron gas cylinder threw off the compass and had me pointing in a totally different direction then where I was actually headed. Like yours, the GPS was unaffected. I found this out by moving the life raft and it was magically fixed. Perhaps something changed in the environment around your fluxgate compass. A new bilge pump or other electrical component will do it as well.

[RolfP]

We had the same issues as Baccanal. We removed the metal near the compass and things worked again.

[Alaska JD]

I very much appreciate everyone's thoughts on my problem. As recommended I've emailed Raymarine and will post their response. I need to check whether my wife put something close to the compass. I didn't but that doesn't mean nothing was put there. I'll keep posting as I get this resolved. Again I appreciate all the input. I know the answer is embedded in the knowledge shared. Thanks. John


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[belizesailor]

Originally Posted by Alaska JD

I made this same post on a different thread yesterday and although it had a number of views there were no opinions or potential fixes suggested. I'm posting it again today with a different title hoping for some input.

Recently I bought a boat with a Raymarine C90 W chart plotter. I worked flawlessly for 1500 miles. Then, shortly after leaving an anchorage I noticed that it was showing me sailing backwards and the autopilot was showing a heading that was the reciprocal of what I was on. Additionally the tide current vector (blue arrow) was at it's largest size even though we were at slack tide. I reset the display to factory settings hoping for a miracle to no avail. The COG is giving the correct information. Does anyone know what the heck happened and how to fix it??

Thank you in advance for any productive ideas about how to resolve this without spending lots of boat bucks.

Ummm...except for the several posts suggesting you confirm there are not objects influencing the fluxgate compass and to then swing the fluxgate compass. As has now been suggested again on this redundant thread. None of this costs a single boat buck.

http://www.cruisersforum.com/forums/...d.php?t=151122