autopilot/compass location

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seawinder

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Joined
Dec 6, 2020
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9
i am very happy with my new to me 2016 44 swift trawler. I am working on an issue where the raymarine autopilot throws in full port rudder as soon as placed on auto. I have upgraded the software, and done the recalibration of rudder. next I would like some help on where the fluxgate compass is on the boat so i can check it. often they are located on a bulkhead away from electrical interference. does anyone know where to look for it.

The stern thruster malfunctioned in an unrelated issue. The quick usa people directed me right away to the tcx box strapped to the motor. It was very corroded inside. This tcx box is just a circut board with no protection from seawater splashing in the bilge. I would guess this is a common failure mode.
has anyone found a way to semi-waterproof it?
 
Stern thruster control. Either install it in a sealed box with seals on the electrical entries or move it high so it does not get splashed. Many electrical enclosures should work well. You just need to pick the size and be absolutely sure the cable entries also have seals. Check with a decent electrical supply house for a good source as they deal with these types of enclosures. There are good H.D. plastic units available so they do not rust themselves.

I also suggest that you seriously look to reduce bilge water splashing about. It can be done.


Can't help with the compass location as that is often left to the installer who may have been an outside source.

As for the immediate turn to Port it sounds like something mine did a long time ago. It blew a power transistor, shorted, so as soon as it got power the boat turned sharply to , in my case Stbd. I figured the reason was the pump had never had its basic set up finished before we bought the boat.
THis may not be your case but ask your supplier. In my case I was able to figure it out and replace the transistors.
Your problem may be something more basic than software updates.
 
The compass module is typically placed low and in the forward 1/3 of boat length away any heavy power cables like BTs.
 
Had a friends boat do that and it was the rudder position sensor. We disconnected it and the problem went away. Never hooked it back up and the auto pilot worked fine. But it could also be a poor location for the compass, ferrous metal or power cables nearby.
 
Most pilots have a rudder indicator in the display somewhere. That's an easy way to test the the rudder sensor. Just turn the wheel manually while watching the indicator to confirm they follow each other.


Similarly, there are various dockside tests that allow the AP to confirm that it has proper command of the rudder. The pump, rudder position sensor, and controls need to work for that test to pass. Give it a run and see how it does.


Last, you AP display should also be able to display the heading from the heading sensor. Check what they reports, and confirm it makes sense. Drive the boat around manually and see if it swings as expected.
 
What model Raymarine autopilot?
Does the manual have a troubleshooting section? If not, go through the installation instructions for dockside setup.
 
My Raymarine AP has the fluxgate compass connected to the brains of the unit (a grey box on the fwd wall of the ER)by the "Seatalk" connection line. Follow that line and identify the components connected to it, till you have located them all. The "Seatalk" line disappearing towards some otherwise inaccessible location will end at the compass.
 
i am very happy with my new to me 2016 44 swift trawler. I am working on an issue where the raymarine autopilot throws in full port rudder as soon as placed on auto. I have upgraded the software, and done the recalibration of rudder. next I would like some help on where the fluxgate compass is on the boat so i can check it. often they are located on a bulkhead away from electrical interference. does anyone know where to look for it.

The stern thruster malfunctioned in an unrelated issue. The quick usa people directed me right away to the tcx box strapped to the motor. It was very corroded inside. This tcx box is just a circut board with no protection from seawater splashing in the bilge. I would guess this is a common failure mode.
has anyone found a way to semi-waterproof it?

Before you continue searching for the compass, do you suspect it has a problem? Not sure how locating it will help much. What do you plan to check when you find it? I assume you have a mechanical analog compass. Does it match what the AP compass says +/- a few degrees? If so, the compass is probably fine. If not, there is a calibration procedure for your autopilot compass that you should perform if you haven't already. This is sometimes necessary if a boat is relocated a fair distance to a new location. However, if your AP is always going to full port whenever you turn it on, it sounds like something other than a less than accurate compass reading.
 
i am very happy with my new to me 2016 44 swift trawler. I am working on an issue where the raymarine autopilot throws in full port rudder as soon as placed on auto. I have upgraded the software, and done the recalibration of rudder. next I would like some help on where the fluxgate compass is on the boat so i can check it. often they are located on a bulkhead away from electrical interference. does anyone know where to look for it.

The stern thruster malfunctioned in an unrelated issue. The quick usa people directed me right away to the tcx box strapped to the motor. It was very corroded inside. This tcx box is just a circut board with no protection from seawater splashing in the bilge. I would guess this is a common failure mode.
has anyone found a way to semi-waterproof it?

The fluxgate compass on my 2018 44ST is located under the helm station. Access is behind the mirror in the guest head. There is a screw at the bottom of the mirror that needs to be removed to open the mirror door. With regards to your stern thruster that area should not have water in it mine is always dry. Check thoroughly for any leaks.
 
thanks to every one for your input. very useful stuff. On the circut board. A new one on the way for 445$ from Quick USA. I will do some things to waterproof it, like seal the areas where wires enter with RTV, maybe tape the areas where lid is screwed on, and them I am going to mount it a little higher than where it is strapped to the motor. Getting rid of the water in the bilge is a great suggestion. The leak in my case is the port rudder post.... see the other thread for this.

On the auto pilot, yup the compass is behind the guest mirror. and most likely is not the problem, because it accurately reflects the direction the boat is pointed. but i am trouble shooting in the order suggested by my local Ray Marine tech. I got all the updates loaded and no change. Tech is coming out in a week, so stay tuned on that one.
 
Update .
The rear thruster is working now with new TCX box from Quick usa. lots of corrosion on the wires and connectors leading to the thruster . In fact the connector providing power was completely corroded. Its a little crazy that the connectors to the pigtails from the TCX box have waterproof gaskets, and then six inches up the line the Beneteau connector is just a wide open connector. In the seaplane world where I do some work, that would be a big no no in the bilge. I also note that the wiring is not tinned copper, which again would be normal in the seaplane world, but just regular copper wire. Very interesting to see once it gets started, how far the corrosion creeps up the copper wire under the insulation. Any way, all connectors have been replaced with heat shrink butt splices or a few heat shrink spade connectors where needed. I kept the quick usa waterproof connectors. I also waterproofed the TCX box. Fittings and everything metal or aluminum back there then doused with CorrosionX which is my current favorite anti corrosion treatment.

On the Autopilot problem, this got solved with an update to the system and a repeat of the "dockside" setup along with recalibrating the compass. The step that finally solved the problem was the one where the autopilot runs the rudder all way port then all way starboard while you watch.
 
It doesn’t take much interference to mess up an autopilots compass. I re-wired a bilge pump one day, not realizing I ran the new wiring too close to the autopilot compass.

First time we were running with the AP when the bilge pump came on, the AP immediately took a hard left!
 
On the circut board. I am going to mount it a little higher than where it is strapped to the motor.

Sorry if I missed something above, but in order to give consistent and reliable heading data, the fluxgate compass should be located as far as possible (or at least several feet) from anything iron and from magnetic fields. Motors have both. That may be the root of your problem.
 
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My old Simrad setup had the rudder indicator start failing intermittently. Led to one or two "crazy ivan" sudden turns when it thought the rudder wasn't where it was expected. I'm in the process of replacing the whole setup. ...and of course the controls use different size holes, so that adds some extra fabricating work...

I've also got an old-school analog rudder indicator, on it's own separate sensor arm attached to the rudders. This is how I noticed the Simrad was wonky, the analog gauge showed straight, but the Simrad sensor was reading hard over to starboard.

I've been using a PG-700 heading sensor, mounted at the waterline (as it's supposed to be) forward in a stateroom berth. But this season I've had an SCX-20 satellite compass added that's supposedly much more accurate (enough so that it allows determining stable enough readings to correct for movement and bottom sonar readings for 3D). So I'll probably decommission the PG-700.

Note, heading and compass sensors ARE sensitive to nearby metals. Doesn't take much to disrupt their accuracy. That and they may require recalibrating. Which usually involves putting them into a calibrating mode and then making wide, slow circles on the water.
 
If it is a fluxgate compass look in the bilge forward of midship. Somewhere you still have some flat bottom. Near the keel.

pete
 
May not be pertinent, but make sure you don't have any magnetized items near the compass. Happened to us with knives in a drawer that was near autopilot compass.
 
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