Autopilot Troubleshooting

[Essobee33034]

Good morning! We have a Grand Banks 36 Classic that we are thoroughly enjoying. She's not perfect but it has been fun getting to know her. One of the bits that we have broken is the autopilot. It is a simrad robertson AP11 heads with what I believe to be the J3000 box. The drive itself is a mechanical drive mounted below the lower helm. When it was working there was a noticeable thump when you engaged the autopilot, as if a mechanical clutch was engaging. This is no longer occurring, and within a minute of asking the unit to steer, one gets an error message on the display "actuator fail".

The unit worked fine for our purposes prior to breaking, so fixing the current one is preferred to replacement. I have found the manuals for the head unit and the installation guide but cannot identify the type of mechanical drive this is. Anybody have any ideas on a troubleshooting guide for the mechanical drive seen in the pictures? It has no label or identifying numbers and may just be a custom metal box for a reversing electric motor.

 

[Portage_Bay]

It looks to me like there is a large solenoid on top to actuate the clutch lever.

I would start with the easy things first like checking the wiring and connections. And the output from the J3000 box to the solenoid as well as the reversing motor signals. Hopefully you have the Simrad manual to identify the connections.

Next get someone to engage the autopilot while you watch. If I'm right that these are solenoid and clutch lever but nothing moves then what you may have learned is there is a problem with the solenoid, it's failed or the wiring has failed. If the solenoid moves the clutch lever then the problem is internal. Bad connections inside the mystery box. Broken clutch. Who knows.

When faced with something like this with no information to go on I take the attitude "It's already broken" and start in. Carefully open and begin to disassemble, lots of pictures and notes as you go. It's probably repairable.

 

[Bmarler]

Agree, if it’s not clunking any more, the solenoid isn’t pulling in. Either the signal is lost, or the solenoid has failed.

 

[GMiller]

Thank you very much! I have removed the motor and without the service manual I will start with replacing the solenoid. Any idea what brand and spec this might be? Does this type of solenoid have a special name? Looks like a ink mark of h8 and 6836 on it, and a quick google search from my phone isn’t immediately revealing.

 

[Bmarler]

Thank you very much! I have removed the motor and without the service manual I will start with replacing the solenoid. Any idea what brand and spec this might be? Does this type of solenoid have a special name? Looks like a ink mark of h8 and 6836 on it, and a quick google search from my phone isn’t immediately revealing.

i would have started by checking voltage to the solenoid. or apply voltage to the solenoid and see if it pulls in.
you can get solenoids like the through Grainger or Mcmaster Carr. easy enough to cross reference by size and voltage.

 

[Essobee33034]

I am hanging wallpaper one-handed, with the control box under deck and the AP controls out of reach. SWMBO was not with me this afternoon, unfortunately. When I turn on the autopilot and engage it there is a slight click audible. I will investigate further when off on Wednesday. Thanks again for your time to respond.