Autopilot problem

[mike66]

My autopilot stopped responding to the controller which is a ST7000. All electronic functions work except the steering. I tried to measure output voltage to the hydraulic drive pump, but didn't get any voltage. I replaced the course computer with a used S2G. Now the hydraulic pump (Autohelm type 1) makes noise when I input a course change of 10 degrees, but the rudder doesn't move. Both upper and lower wheels turn the rudder fine and the system is full of fluid. The rudder indicator woks fine. Can the autopilot pump itself fail? I'm not looking forward to draining the system and replacing the drive unit. Any suggestions?

 

[Comodave]

Did you measure the voltage to the pump while you were giving it a rudder change?

 

[mike66]

I tried and couldn't do it solo. I'll try again when there are two of us. The motor responded when I gave it 12v, but the rudder didn't move. Can the hydraulic pump crap out or get get a valve stuck?

 

[Comodave]

Yes, it is tough working alone. Don’t know if they fail like that or not.

 

[wkearney99]

One handy trick if you've got an iPhone and Apple watch Apple watch is use the watch as a remote to the camera on the phone. That or use a Wi-Fi camera to be looking at the gauge from any other kind of device that can connect to it. I keep a 12' length of wire handy with alligator clips on each end. That way I can use my meter from a more convenient location..

 

[Comodave]

One handy trick if you've got an iPhone and Apple watch Apple watch is use the watch as a remote to the camera on the phone. That or use a Wi-Fi camera to be looking at the gauge from any other kind of device that can connect to it. I keep a 12' length of wire handy with alligator clips on each end. That way I can use my meter from a more convenient location..

That is a great idea.

 

[mike66]

So motor out voltage is present when I use the +/- 10 degree buttons in autopilot mode, the motor makes a lot of noise (way more than usual) but the rudder doesn't move. I cracked one of the hydraulic hose connections and got fluid, so I don't think that's the problem The system is topped up and both wheels work.
I guess it's time for the job I didn't want to fo...replace the drive unit. Does anyone know if all the type 1 12V pumps work with a S2G course computer?

 

[Comodave]

I would look at the current pump and see if it is labeled with the type. Mine has a label that says Type 1. Usually most any Type 1 pump will work, if you have a Type 1 now, but I would use one from the autopilot manufacturer. Another thing you could try to test the pump is run a +12 wire and a ground directly to the pump and see if it moves the rudder when voltage is applied directly to the pump. That way you have eliminated all of the autopilot stuff and if it still doesn’t turn the rudder it just about has to be the pump unless the rudder is jammed. But I understand you can turn the rudder with the steering wheel.

 

[mike66]

I ended up replacing the pump with an Octopus. Hooked it up today and refilled. Seems to work at the dock, so I think I'm okay. My old course computer was probably okay, but the upgrade to a S2G might be better. I'll find out over the next couple of weeks.
Thanks all for your help!