Chartplotter Heading 180 degrees off!

[Segler56]

For some unknown reason, my Raymarine Chartplotter model RL 120 and Autopilot indicate that my heading is the exact opposite of what it actually is(off 180 degrees). I have read through the manuals - believe the chartplotter is feeding this to the autopilot, but I can't find a way to correct it. Its been like this now for about a month. Has anyone ever experienced this - and found the cure?

 

[Rick I]

For some unknown reason, my Raymarine Chartplotter model RL 120 and Autopilot indicate that my heading is the exact opposite of what it actually is(off 180 degrees). I have read through the manuals - believe the chartplotter is feeding this to the autopilot, but I can't find a way to correct it. Its been like this now for about a month. Has anyone ever experienced this - and found the cure?

Is your fluxgate compass mounted backwards? Sometimes this may happen if the compass is mounted on a fwd bulkhead instead of an aft one.

 

[Segler56]

Hi Rick, and thanks for the suggestion. No, don't think that's it. I have had the boat for 3 years and this problem started a month ago. The GPS feeds data to the chartplotter and to the autopilot, and suddenly its 180 degrees off. Its likely a calibration issue - just can't find out how to do it!

 

[Mike B]

Gosh I've seen this but can't remember what fixed it. Here are some potential fixes. Have you recalibrated the flux gate compass? That's where you put the system into calibration mode and do slow circles until it tells you it's complete? Another thing to try is the compass heading offset setting. You should be able to do a complete systems reset which should also fix it, although you'll want to take note of any waypoints, etc since you'll lose all of them with a master reset.

 

[Segler56]

Mike B and Rick, thanks for these ideas. I have spoken with other sailers in my marina here in Galesville, and everyone's opinion is that the flux gate compass has been affected somehow. Will get to work on it next weekend.

 

[Ron20324]

The usual problem is a wire reversal between the antenna and cpu or cpu and display. But you said this was working previously. Are you sure no one has been in the wiring? Or maybe you're driving backwards???

 

[Mike B]

Make sure nothing metallic has been installed or even placed near the fluxgate compass. If there has been remove it or in the case of an installation re-swing compass to correct it.

 

[SoSound]

Perhaps not this exact problem, but similar in the sense that it was off by 180 degrees. When I first tried building a route from my chartplotter software, I built and printed the route in reverse order. That ended up being exactly the opposite of what I was expecting to see.