Autopilot Issue This Weekend...HELP Needed

[brewster16]

This past weekend after scrubbing my bilge from top to bottom I suddenly had an inoperative Raymarine ST8001 autopilot. The unit powers on and gives me a heading in standby mode but wont hold that heading when engaged to do so. I know virtually nothing about AP's but read about "rudder reference transducers" and "fluxgate compasses." Could I have inadvertently disconnected something when cleaning the bilge that would mess up my autopilot?

 

[gerryb]

There are connections to the AP motor as well as a rudder position sensor in the bilge.

"Could I have inadvertently disconnected something when cleaning the bilge that would mess up my autopilot?"

Yes.

 

[bmac]

When you engage (by which I assume you mean place in AUTO) the AP, do you hear the AP hydraulic pump (mine is under the helm) actuate? Does the AP heading indication change over time as you deviate from the course setting when you go to AUTO? Or change drastically when you go to AUTO? Can you see changes in the rudder position as you deviate from the set course while in AUTO? If you can hear the hydraulic pump actuating but get no rudder position change you may have disconnected the rudder position indicator (located on one side of your rudder cross arm). If you see a wild swing in heading when you put the AP in AUTO you will need to go through the fluxgate calibration process again. If you see no change in heading but no reaction in rudder position check the hydraulic pump fuse. Good luck.

 

[brewster16]

Thanks Brian....I'll be looking at your suggestions this weekend. I really think I may have disconnected the rudder position indicator cable connection when scrubbing out the bilge this weekend.

 

[Team PCBeach]

The rudder reference transducers let the auto pilot know the position of your rudders, fluxgate compass tells the AP your current heading. The compass is usually located low in the boat near the mid-line. In my 360DA it is in the floor storage area right outside the head door.

My guess is you have disconnected the pump somehow. A good test would be to engage the AP then add 20 degrees to the heading and see if your steering wheel turns. If it doesn't you have a pump issue.

 

[bmac]

The steering wheel does not turn with the AP engaged (at least it never has on any of my 4 boats with AP). The hydraulic pump provides an input to the hydraulic system downstream of the steering wheel impulse lines to the same system.

 

[ttmott]

The rudder position reference for the AP is not essential to it's function; it makes it more "efficient" which in the long run, saves fuel. If the rudder position wiring were to be shorted out then who knows what will happen.
The AP electric pump for these systems are typically located near the helm so the wire lengths from the AP course computer (probably an Smartpilot S3G) are as short as possible.
As a test disconnect the rudder reference wiring from the Smartpilot course computer and see if that corrects the issue.
The course computer should also have a GPS input via NMEA 0183 and a fluxgate compass input, both of which are needed for correct operation.

 

[Woody]

This past weekend after scrubbing my bilge from top to bottom I suddenly had an inoperative Raymarine ST8001 autopilot. The unit powers on and gives me a heading in standby mode but wont hold that heading when engaged to do so. I know virtually nothing about AP's but read about "rudder reference transducers" and "fluxgate compasses." Could I have inadvertently disconnected something when cleaning the bilge that would mess up my autopilot?

On my boat the autopilot pump is mounted in the bilge on the strbd side above the batteries. Were you cleaning and spraying water in that area? When you say it won't stay on it's heading I'm wondering if it's trying to steer at all.

As far as your rudder indicator goes run the boat straight, check the instrument display and see if it's on -0-, turn the wheel lock to lock and see if the display represents that.

If your rudder indicator was OK and working you could engage the autopilot and simply watch the display to see if the autopilot was attempting to make steering corrections necessary to stay on course.

 

[FootballFan]

with the ignition in the run position.

Engage the autopilot. Then as said above, add 10 or 20 degrees using the + button.

You should see the rudder indicator swing on the AP display. Steering wheel will not turn.

I had an issue with a bad connection earlier in the year. Autopilot would engage but as soon as it needed to move the rudders it give an error message on the AP display.