Troubleshooting Power Pilot Autohelm 6000

[Steveg353]

This is an old model A/P that was installed on our 38' trawler many years before we owned her. It is not tied into GPS. There is a rotating rudder sensor with a simple dial rudder angle indicator at the upper helm wheel...not on the control panel.
Here is the story:
In the past year we have cruised 4500 miles and I would say that 70% of that was done under auto pilot. Not one issue with the A/P was experienced.
4 weeks ago we parked the boat. This weekend when I turned on 12v power to the electronics the rudder angle indicator pegged out to port. Turned off power and the dial returned to center.
Honestly I thought the indicator was stand alone and wasn't connected to the A/P. Wrong! We took the boat out and when I turned on the A/P the boat went hard to starboard.
We came in and I realized how much I used the rudder angle indicator when docking.
After reading about the rotating rudder sensor I performed the ohms test on the sensor and it is functioning correctly.
I am looking for suggestions on any further troubleshooting ideas.

 

[C lectric]

N one yet? Don,t know your system but?

Check wiring between sensor and A/P control. Just because resistor is ok does not mean control is getting proper signal.
How is unit mounted? Could something g have moved causing a misread?
How is sensor arm mounted? Same comment as above.
Have you tested the volt variation on the output lead while turning the sensor shaft. Maybe wiper inside is haywire.

 

[Comodave]

A friends boat has an older auto pilot, don't remember what brand, that started going hard over to starboard. We did some simple troubleshooting and it came down to the rudder angle sensor. We tried unplugging it and it stopped going hard over. He is currently using it without the rudder angle sensor and he says it works fine without the sensor.

 

[petdoc4u]

We tolerated a similar problem which we thought was associated with the autopilot control head. Turned out to be a malfunction in the autopilot computer. Resolved the problem by replacing the computer with an upgraded refurbished model found on Ebay. No further problems for past 3 seasons. Good luck.

 

[Steveg353]

I did disconnect the rudder sensor and the A/P seemed to function correctly. I thought that since the rudder sensor passed the resistance test it was ok. Apparently this is not the case as C lectric mentioned above.
Now my question turns towards rudder sensors.
Because the A/P is so old, do I have to find an old sensor or will a new Raymarine rudder sensor work? I would assume that they still work the same but you never know.

 

[LaBomba]

Not sure if you are interested but I have a complete Autohelm 6000 that I bought from a friend and never installed it. Likely worth it for spare parts if you don't intend on removing it. Let me know.

 

[Sammy_Mariner]

???s from brand Newbie...

Recently acquired a 38FT Orient Mariner 2005.
Please, accept my ignorance if I don't make the correct reference or use the proper terms, anyway, but, will forge ahead....
The slave controls (depth finder and bow thrust) on the bridge are not responding as they should. Could this be a situation of corroded connection between those in the cabin???

KenA
Severna Park, MD

 

[C lectric]

Steve353. Suggest running new wire in bypass between rudder sensor and control. Doesn't,t have to be pretty as it just a test. If still doesn't,t work then either sensor has failed, or control head not reading. Do not discount possibility of something mechanical at sensor is haywire. Arm on sensor shaft shifted, sensor body shifted, etc.
I would also look HARD at any splices of any kind no matter how they look. I have fixed many issues by simply reterminating wires. Oxidation inside crimp barrels can obscure the often weak signals from sensors.


Sammy. Yes. But should have started your own thread as now answers must be I'd,d and can be confused. No worries but easier for all when issues are kept separate.

 

[Sammy_Mariner]

Steve353. Suggest running new wire in bypass between rudder sensor and control. Doesn't,t have to be pretty as it just a test. If still doesn't,t work then either sensor has failed, or control head not reading. Do not discount possibility of something mechanical at sensor is haywire. Arm on sensor shaft shifted, sensor body shifted, etc.
I would also look HARD at any splices of any kind no matter how they look. I have fixed many issues by simply reterminating wires. Oxidation inside crimp barrels can obscure the often weak signals from sensors.


Sammy. Yes. But should have started your own thread as now answers must be I'd,d and can be confused. No worries but easier for all when issues are kept separate.

Thanks for the heads up on this post. 100% agree should have been a new thread. Didn't realize I was stepping onto someone else's thread....
My Apologies ......

 

[C lectric]

Sammy

I was a bit to cryptic. I,m using a small tablet, typing is a pain so tend to cut short answers, sometimes too much so.

The YES was in answer to your question about corrosion possibly causing trouble between the two control stations.
Sorry if I was not clear about that.

 

[Sammy_Mariner]

Sammy

I was a bit to cryptic. I,m using a small tablet, typing is a pain so tend to cut short answers, sometimes too much so.

The YES was in answer to your question about corrosion possibly causing trouble between the two control stations.
Sorry if I was not clear about that.

No worries. I'm thinking a corrosion issue somewhere in the chain. Thanks for the clarity.