Another AP Autohelm 5000 issue

[Express]

Hi everybody,
Another Autohelm 5000 (analogue) issue. A brief history of the symptoms:
I’ve had the unit for 10 seasons (came with the boat) and liked it a lot, until it stopped working last year; With the AP ON, but disengaged at the remote (aux) unit in the cockpit, the control system supposed to track the course, but when engaged at some point (again from the cockpit) it would steer the boat violently in the direction of some earlier course. I had to resort to resetting AP every time I intended to use it, but after a while even that didn’t work. Guessing that the internal compass seized up, I opened the main control unit (needed Cap Dan’s hint to finally do it – no word in the user manual …). After disengaging the belt I turned the compass cylinder by hand; the Pilot Lights were responding and at one point both went OFF. I turned the unit 90 deg, turned the compass neg. 90 and the lights went OFF again. However, the compass cylinder would not move (by itself) … L
One more thing; after opening the unit I didn’t noticed any rust, dirt or oil film anywhere …
Any idea? (short of “it’s time for a new one” ;-)
Thanks,
Peter

[senormechanico]

Sounds like gunk causing sticking.
Isn't there a little rubber belt in there?
If there is, it's probably stretched and not working very well.
(From memory of 15 years ago.)

[Express]

Thanks Senormechanico, Love your "Top 10 reasons... ;-)" - this is WHY I'm posting this ask-4-help now and not in November, when all was fresh in my memory...

But to the issue: yes, there is a rubber belt and it seems to be in good shape: compass turns the steer knob’s shaft and vice versa. When I disassembled the unit (in Nov.) it looked clean, but I wiped it and polished the contacts anyways … the compass does not rotate (by itself). I don’t have a service manual – so I simply don’t see where to move from here…

P/

[Capn Dan]

The compass can be rotated in two ways. 1) by the steer knob which moves the oring that goes around the compass and 2) by using the remote in the cockpit. When using the remote, there is a small motor inside the control head that rotates the steer knob. It is connected to the brass shaft of the steer knob by a rubber bushing. This bushing gets weak and the motor will no longer rotate the steer knob shaft.

[Capn Dan]

Peter,
It has been a while since I worked on one of these, but I do not think that the compass should set (both red and green lights out) by turning 90 degrees. Maybe 180 would do it but I don't remember.

[Express]

Capn Dan, Thank you for picking my thread! Judging by what I've read on this site (I'm a new member) you're probably my last life ring on that ...
Re 1) yes that works i.e. I can rotate the compass by turning Steer Knob (via brass shaft and that o-ring type rubber belt between that shaft and the (black) compass cylinder. It doesn't work the other way around: Compass is not turning when the unit is off the boat C.L ... i.e. (I think) to the AP little brain the boat went OFF COURSE and the Steer should be corrected... ???
Re 2) perhaps I should disconnect the Aux (cockpit) unit to eliminate that possibility ... still that "compass not following the course" is my concern - what do you think?

BTW I sailed only once on Tartan 33R ... (Youngstown regatta) WOW!

[Express]

Dan,
When I tested the unit - still powered, on the boat I did not use the cockpit unit; only the main control (in the cabin). Still I could not get the compass to set / move the Steer shaft to the heading position ... even after I opened up the box (with the help of your tip...) so I could watch the action ...
The Pilots Lights would indicate the direction OFF course, but the compass would not turn to "force" the steering action...

This is probably not very clear what I'm trying to explain - is it?
Peter

[senormechanico]

Disconnect remote controls.
If it works ok then, the problem is most likely salt leakage in wiring/switches.

[Capn Dan]

The compass should only rotate when you move it by either:

A: the steer knob
B: the aux remote in the cockpit.

It is never moved by the autopilot without your input. It remains stationary until you make a course correction.

Try this at the dock:

Set the SEA knob mid way. Use the steer knob to extinguish both red & green lights. Push the duty button. Now rotate the control box left then right. You should get one of the lights on and movement of the rudder as you rotate the control head off the position where you originally “set” the compass. When you go back to the position where you “set” the compass, both lights should be out and no rudder movement.

[Express]

Hello again,
Sorry, but I wrote my entry (end of this post), when I was on the boat and before I checked Dan’s last suggestion, so I start with some clarifications: The boat is still on the cradle (winter storage) – but of course I can conduct “at-the-dock” test that you are suggesting – and will do it tomorrow, and report. When I’ve said that the compass is not turning by itself, I meant it is not responding (while powered and on SET) to the rotating movement of the control unit…
My question: I’ve thought that the compass, once on SET mode should follow the boat’s course (i.e. position of the control box that is attached to the boat) regardless whether the rudder is engaged or not …?
When it was working properly, after the SET button was pressed, the Steer knob would rotate (presumably driven by rotating compass through the o-ring belt) until both Pilot Lights were extinguished, indicating that the AP/compass “is aligned” with the boat’s present course. IT DOES NOT DO THAT ANYMORE. Only the Red (or Green) Pilot Light comes ON – signaling (as I understand) that the boat is on different course than the compass is set to … but the boat’s course IS the course I want to follow … ;-)
I will try, Dan your test tomorrow, perhaps it would give you more info on what’s might be wrong. If all go well - I will report my findings on this forum tomorrow night.
The following is what I did on the boat yesterday:
I hooked up the AP control unit (aux disconnected as Steve’s suggested) and re-did the tests that I described in my original post. This time the o-ring belt on and fluxgate compass, so I could turn it (manually) by the Steer knob. The results agree with what I’ve described earlier; with the power ON and SET button pressed, one of the Pilot Lights went ON and stayed. Steer knob NOT turning. As I turned the Steer Knob to align Fluxgate Cylinder with the boat’s bow, the lights had extinguished.
I then turned the unit 90 deg; Pilot Light went ON indicating the direction, in which to correct the course. After turning the compass (again manually via Steer knob) by negative 90 deg, the lights went OFF. I’ve repeated that with different angles with exactly the same results…
The problem remains: The fluxgate compass does not turn by itself when the control unit is rotated :-(
Someone on another thread has suggested taking it apart and cleaning – which I did last year, but will do again today and report tomorrow…
Dan, in yet another thread (re AH5000) last year, you’d mentioned that you might have a copy of the service manual for this unit – if so, would you be willing to share it??
Thank you guys for your patience in reading my long entries in this forum. Looking forward to your comments,
Peter

[Capn Dan]

Peter,

Sorry, I misunderstood your earlier post.

I repair autopilots but generally do not work on the 5000 so my memory has faded somewhat regarding their operation. They are a beast of their own and very different from all other Autohelm / Raymarine autopilots.

If the steer knob will not move during set then you should test to see if the motor that drives the steer knob is good. Probably the simplest way is to use the remote. Manually rotate the steer knob while in set until the lights are out, go to duty, now make a course change with the remote and see if the steer knob rotates. Also, test by opening the head and test the voltage at the motor wires. Do this while in set and one light on.

If the motor is bad, I have one. If you are not getting power to the motor while in set, it is probably ready for the bin. PM sent about manual.

[dbartilson]

Buying a boat with an autohelm 5000. Would like to purchase a remote control. Wired is ok. Can't find any unless the wireless unit (Raymarine S100) works with this unit. Boat is 1981 so it's probably not an ST5000 but need to verify the age of what I'm getting.