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jamie mac

Veteran Member
Joined
Oct 4, 2012
Messages
83
Location
canada
I have a ray marine auto pilot that seems to be searching for its heading back and forth but it never settles in. It worked great when I first got it. I installed a battery for the bow thruster within 2 feet of the compass for the auto pilot would this be the reason it is searching?
 
Yes. YES

Have you watched why it doesn't settle? If it's the compass heading than definitely.
Even if not, than probably.
 
Battery is lead mostly, no iron, so I suspect not, but test. Normally we think of non ferrous metals as non magnetic meaning lead is non magnetic.


However the flowing charging current and voltage to the thruster battery will create a magnetic field around the conductors and in the battery itself. Maybe that is strong enough to upset the compasses ability to sense the earth's field and thus give a good signal to the A.P.

This effect would most likely be strong on one heading and weaker at 90o so should also affect the compass more or less depending upon heading unless the wiring and battery partly surround the compass.

Try disconnecting the battery, ensuring that the leads are well spearated and cannot get into anything, and test. Pull the fuse.
If the problem quits and the A.P. works again then you have your answer.

If not then try removing the battery and retest.

If either test works then you must decide whether to move the battery and conductors or the compass.

If the above works There is one other possibility and that is twisting the positive and negative battery leads around one another. This will cancel out the fields around the conductors. You may have to lengthen the leads to do it so try just killing the power first. Maybe that will be enough.

If neither helps then the A.P. or compass likely has another problem coincidental with the battery install. Did you monkey with, damage or disturb the compass wiring in ANY way while installing the battery? These leads can be somewhat fragile.

Yes, I'm reaching here but have seen my own compass foobarred years ago by a knowledgeable??? installer installing a small speaker close to my compass. Compaii do not like that.
 
If it DID work and now it doesn't, think hard about what you changed or moved last. I put a steel scuba cylinder too close to mine and wondered why response slowed down. I moved the cylinder and was good as gold again.
 
Check the rudder feedback arm on the rudder...they often pop off Raymarines...

I know it may have had nothing to do with your battery install...but they have an annoying habit of doing just this...driving you crazy...
 
Certainly isolate the thruster battery from the compass, especially if the compass or battery is a recent install.

Swing the compass, the instructions are in the manual. If the deviation after a successful swing is greater than 15 deg you need to relocate the compass according to the manual on my Ray ST 6001+. Mine is 18 deg and works fine.

You can also change the response level. Level 2 more closely follows a heading or track but will adjust the rudder more frequently to do so. It's easy to do and can be done on the fly.
 
Jamie,

I have a first generation SPX autopilot (old enough there is no model number on it) that I am replacing for the same reason. It really wasn't the compass, as the compass heading on the autopilot control head showed consistent headings while the autopilot decided to go elsewhere. It would start off fine when the course was selected and then was slow to respond with course corrections. I went through enough different configurations of rudder response, counter rudder, sensitivity, that in the end nothing seemed to matter. There were days it would work just fine for a few hours and then would start wandering. It had a difficult time handling cross winds. It was lucky to maintain course on some days +/- 5 or more degrees. If you followed my course line on a radar, you might have probable cause to stop me. There were no software updates and the cost to replace the course computer was only $200 less than putting in a new EVO unit since my hydraulic pump was just fine. So that's is what I am going to do in a couple of weeks. If you need a Fluxgate sensor I'll have one available as well as a 7001 control head if you need parts. I have a P70R at the upper helm and decided I wanted another one.

Tom
 
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