Raymarine A3G AST -Drive Stopped

Duane Siegfri

After working on my self-steering gear failure, I thought I would put some info in the "Files" section.  If you see anything I could improve on, or that is in error, please let me know.


For future reference the way to trouble shoot the Raymarine S3G on the Super Maramu with two steering motors (and other self steering products I suspect):

If the self-steering isn't working it's either the:
-Rudder Sensor
-Fluxgate Compass
-Drive Motors (the SM has a rotary drive over the sink, and a linear drive in the aft cabin on the rudder quadrant)
-Course Computer (Raymarine S3G in my case)

====Alarm Messages
-Note that the Raymarine "SmartPilot Series Commissioning Guide" has the list of "Alarm Messages" in Chapter 4 with their likely cause.

====General Checks
-Check for a blown fuse in the S3G Course Computer (above sink screwed to bulkhead, remove the lower door by  rotating the locking screw in the middle by 90 degrees).  In the S3G there should be spare fuses on the upper left under the lower door.
-Check that the rudder sensor is firmly attached to the boat (under the aft bunk attached to the rudder quadrant),
-Check that you have power to the S3G with a voltmeter on the larger wires labeled "Power".  If your batteries are low the S3G may not function properly.

====To determine if it's a drive motor:
-this is especially suspect if one drive motor works and the other doesn't.  If you only have one, might as well check this.  I understand motor brushes are a frequent source of problems as are drive belts.  Sometimes the dust from the motor brushes causes problems for the motor that results in failure to engage.
-turn off the breaker to the self-steering
-check with a voltmeter that there is no voltage on the power wires
-disconnect the "Power" wires in the S3G Course Computer (they are clearly labled) (take note which color wire is port and which is stbd)
-disconnect the "Motor" wires in the S3G Course Computer (clearly labeled) (take note which color wire is port and which is stbd)
-connect a "Power" wire to a "Motor" wire, repeat for the other "Power" and "Motor" wire.  I used a battery cable connector (shaped like a clothes pin).  You could also use electrical tape.  Be sure the positive and negative wires are separated and cannot make contact.
-turn the self-steering breaker on.  One motor should run.  Note that the clutch will not engage (because you disconnected the power to the S3G) so the wheel won't turn, but you should hear the motor run if it's working properly.
-turn the breaker off, and switch the A/B switch to the other drive.  Turn the breaker back on, and the other motor should run without the clutch engaged as above.
-if one of the motors doesn't run, it has a problem.

====To determine if it's a clutch:
-If the self-steering will not hold the wheel still when you press "AUTO" on the Control Head, it's the clutch.
-The Raymarine clutch is 12 volts, be sure to check that the fuse is in the 12V position.  If not you may have a burned out clutch.

====To determine if it's the Rudder Sensor:
-with the breaker on, turn the wheel back and forth.  You should see the rudder position indicator on the Control Head (at the helm) change accordingly.  If it doesn't it may be the problem.

====To determine if it's the Course Computer:
-if the problem occurred regardless of which drive motor was selected by the A/B switch; and
-the clutch engages and holds the wheel; and
-if the "drive motor test" above showed both motors run, then it's likely the Course Computer.  
-One other test is to: turn on the breaker for the autopilot; put your voltmeter test leads on the "MOTOR" wires; and have someone else hit "+10" at least three times; observe your voltmeter continuously.  If no voltage is output to the "MOTOR" wires, then the problem is the Course Computer.  If voltage is output (it could be intermittent and that would not signify a problem) then the problem may not be the Course Computer.
-I'm told the Raymarine X30 is the next gen replacement for the S3G and that it's a drop-in replacement. 
-Dan Gerhardt c250"at"mydurango"dot"net has repaired course computers for several people.  He may have replacement course computers available.

====Fluxgate Compass
-This one I'm not sure about, but if the problem was with the Fluxgate Compass, you would probably have an errant compass reading on the Control Head.

====Alarm Messages
-Note that the Raymarine "SmartPilot Series Commissioning Guide" has the list of "Alarm Messages" in Chapter 4 with their likely cause.

---In amelyachtowners@..., <dancarlson367@...> wrote :

Hi Duane,  

I just replaced my S3G with a used X30 from Craigslist and it is working smoothly.  The mounting holes are about 2cm closer together so you need to drill a new mountin hole.  The bis for connectin tje wiring is much better on the X30.  I will send the old S3G to Dan to rehab and serve as a spare.

Regards, Dan Carlson
Sm#387, sv BeBe

On Sun, Apr 30, 2017 at 6:54 AM, sailor63109@... [amelyachtowners]
<amelyachtowners@...> wrote:

Hi Bill,

I guess I wasn't clear, I meant the Autopilot would not turn the wheel while on "Auto".  The clutch engages but the Autopilot won't turn the wheel in response to "+10".

I've been in contact with Dan G.  He suggested I disconnect the power and motor wires from the S3G and hook them up directly to be sure the motors on the drives were still operational.  I used the breaker to turn them on and off, and both motors work.  Running the motor this way the clutch does not engage (because the S3G has no power), but you know the motors work.

He doesn't have a spare S3G, but does have an X30.  It sounds like the X30 would be "plug and play" so if the S3G doesn't work I have a good way to go.

Thanks for your help,

Duane Siegfri

Update & Solution:

NB:  There is a flaw in the S3G that Raymarine issued a technical update for.

Dan Gerhardt diagnosed the problem with my S3G Course Computer.  There was a flaw in the programming that could result in a "Kill" signal that disables the unit for no discernible reason.  The solution was contained in a technical update from Raymarine but had never been uploaded to my unit.

If you have the S3G and you are having other work done on the electronics you might want to have them check for the technical update.  The kill signal can happen at any time.