Raymarine Heading sensor incorrect

[SVSeaDog]

Hello and good day,
I have a Raymarine autopilot system. The autopilot system was working fine the last few years. Then the heading is pointing the boat in the wrong direction causing the autopilot to go bananas trying to move the heading to the actual course.

System consist of Raymarine Axiom displays, EV1 heading/compass sensor, HS5 Seatalk network switch, rudder indicator, and ACU400 linear drive controller.

I have tried a total of 3 EV1 heading sensors and they all malfunction in the exact same way not showing proper heading alignment. I have tried a new HS5 network switch. The only thing I haven’t tried is to replace the ACU400. If I manually turn the EV1 sensor I can align the heading to where the system will operate, but as soon as I turn the system goes bananas again. I have also recalibrated the system a few times to no avail.

If you have any advice or knowledge on the subject I would greatly appreciate it.

Thanks,
Brent
SV Sea Dog

[CrispyCringle]

If you've tried multiple sensors, maybe its the sensor location, or a piece of equipment near the EV1 location that affects it when turned on?

[fxykty]

Are you absolutely sure that there is not something metal that has recently been moved within 0.5 metre of the EV-1? For one, let alone multiple units to malfunction is very strange.

Do you still see heading on your instruments or on your plotter? If yes, does it look correct and steady? Then not an EV-1 problem. If no, is it no longer on your network and not available for selection? Then likely an EV-1 problem. It is possible that there is an issue with your MFD connection through the HS-5 to your Seatalk network, but that would only affect the pilot if you’re driving it from your MFD.

The ACU-400 is a consumer of heading data so unless it is failing (if you’ve already confirmed that the EV-1 is working properly) it has nothing to do with bad heading information. It is unfortunately an expensive component to replace.

[rslifkin]

Originally Posted by CrispyCringle

If you've tried multiple sensors, maybe its the sensor location, or a piece of equipment near the EV1 location that affects it when turned on?

Agreed, it sounds like the sensor isn't mounted in a suitable location, or something has been changed or added nearby that's preventing the sensor from working properly. I'd try moving it to a different location and see what happens.

[SVSeaDog]

The sensor location is where it has always been in the ceiling. No new metal has been added to the boat. I also verified no kids metal magnets or any metallic toys are anywhere near where it is mounted in the ceiling.

I don’t believe all three EV1s are bad, I think they are all good, but some other issue is causing the issue. Maybe wire, maybe a Splice T, maybe the ACU400? I am grasping at straws at this point. I have swapped out the HS5 Seatalk and it doesn’t make a difference.

The heading is constantly displayed on the MFD but it just doesn’t display correctly unless I manually turn it to the correct position.

[Bellinghamster]

I had a similar problem with my EV1 last month. After working fine for several years and nothing changed in the systems or nearby storage the heading shifted to about 20 degrees off. After first verifying that no magnetic interference was the cause, then a bunch of time trying to determine if somehow mag deviation was being added by my Garmin MFD to already-corrected data I concluded the data coming from the EV1 was actually wrong. I read somewhere that the EV1 auto-determines magnetic deviation and that turning a slow 360 degree circle is necessary for it to do so. So I did a slow loop and it fixed the issue. It sure seems like that should be top center on Raymarines support page, but I read about it elsewhere. Everything I could find on Raymarines support indicated I needed a Raymarine autopilot to initiate calibration, which I don't have. Turning the circle fixed it and it continued to work perfectly for our next 2 week/500 mile trip.

https://support.raymarine.com/s/arti...language=en_US

[barnakiel]

This is not highly likely 3 different sensors are off.


Maybe there is a metal object nearby. Maybe a connector is wrong. Maybe the software settings are off.


etc.


Pls note the heading off (by a margin) still allows you to use the AP. The number (course) may be off by the pilot will stick to whatever angle you want - just press AP ON when the boat is heading the "right" way.


barnakiel

[Hartleyg]

Hello Brent,


One thought - is it possible you've downloaded a firmware update somewhere in the system? If you do, its always best to start calibrating your autopilot like you just bought it - go through the whole process.
If you have another instrument in the system (i.e., an i70 display) you can program it to show the heading it is getting from the network - if that looks good, then the problem is with the MFD.
Is there a chance something else in the system is producing a heading PGN on the network? having two devices sending contrary info can cause all sorts of issues. Unplug the EV1 and see if you still get some sort of heading - worth a shot, anyway.


Best,
Hartley
S/V Atsa

[Opie91]

Did you add any lighting or something electrical near it?

[clownfishsydney]

Sometimes the fluxgate compass can just get out of whack. Find the manual and do a reset. Normally need to do some tight circles. That fixed my problem.

[sinnerman]

All of the above.
Check for metal or LED LIGHTS (they emit a lot of garbage electromagnetic interference).
Calibrating the compass " Compass Linearization" ...


Cheers

[Eight Sails]

Originally Posted by barnakiel

Pls note the heading off (by a margin) still allows you to use the AP. The number (course) may be off by the pilot will stick to whatever angle you want - just press AP ON when the boat is heading the "right" way.

Not necessarily. That may depend on other components in the system, not just the heading sensor. It also assumes that manually engaging the AP to follow whatever heading the boat is on is enough to satisfy the skipper's normal requirements. If you normally have the AP follow a route, steer to a waypoint or steer to the wind, maintaining the current heading is at best a temporary workaround. When the third-party (Quark-Elec) heading sensor on my boat went wonky after a couple of years and re-calibration wasn't possible, I found that my B&G AP wouldn't even follow a fixed heading--I'm not sure why.

Since OP has tried several replacement EV1 sensors without eliminating the problem, its highly unlikely the EV1 is at fault. If you can borrow a different brand of N2K networked sensor from another boat, try substituting it for the EV1 and that will confirm whether the EV1 is at fault--or its something else in the system, for example a bad connection or cable, missing terminator, or AP computer fault. To rule out magnetic deviation from nearby objects, try installing the sensor temporarily in a different location; maybe you're sure nothing has changed but, if you're like me, you've learned the hard way to assume that assumptions are the least reliable component in any system. To rule out faults in the network, run a new cable directly from the sensor to a central point, bypassing the existing cabling.

As others have suggested, disconnect the EV1 sensor and check to see if magnetic heading data may be coming from some other source; its a long shot but if, for example, you have an older, spare autopilot with an embedded heading sensor installed, you might find the source of the problem there. In particular, you might find that an unsuspected change in output filtering is allowing the old AP to send heading data to the network, which maybe it wasn't before. I still have an ancient Autohelm wheel pilot installed as spare, after installing a new B&G AP under the cockpit. It originally wasn't connected to anything else and for years I did depend on activating it with the boat headed in the "right" direction. When I happened to add a SeaTalk bridge and connected the Autohelm to the network, just to see if I could make it work, I encountered some filtering and control issues due to the presence of two heading sensors.

[sailingharry]

Not sure if this helps, but our AP worked brilliantly, until we headed off on our first long distance cruise -- and in the first hour the boat was uncontrollable (on the Chesapeake Bay). Turned out that in our haste to get underway (last minute scrambles....), I placed a big recovery magnet on the cabin sole, just over the sensor, and as the boat rolled it would slide and drive the sensor bananas. Probably not your problem -- but a pointer to look AROUND the problem you are experiencing.

[SVSeaDog]

Got it resolved. The issue was it needed recalibration. But the compass lock and calibration lock was set to on, not allowing it to recalibrate. When I turned those locks off, and recalibrated it, it resolved the issues. Thanks for all the inputs and pointers.

[sailcrazy]

Following. We, too, have a Raymarine autopilot, that has been "kicked off to the right by about 35 degrees" for several years. We compensate by operating in heading mode only, making 5-10 degree changes left or right manually, based on the track line on our chartplotter, not course following; for coastal cruising it works OK....even if it's not right!