[CA] [CA11] st5000+ problems after re-commissioning

[Tizor]

I've searched the forum, but still in need of ideas. I have an st5000+ with a Type 1 pump, and linear rudder position indicator integrated with a Hynautic 3-line hydraulic system. It has always worked just fine. Earlier this winter, I tore apart my aft bilge below decks (29' Blackfin FB sportfisher) to replace gas tanks, battery shelves, rudder arm tie bar, propeller shafts, props, etc. During this effort, I removed the steering ram (Sea Star, Model BA125-9HYK19) as well as the Linear Rudder Reference Transducer (Raymarine M81188) to gain better access to stuff. After 90 days or so of being disconnected, I re-installed the ram and the rudder reference transducer and bled the steering system via the Hynautic helm pump and its relief valves.

In the past, I have performed the "Compass Swing" automatic deviation correction procedure (20 degrees) and the Heading Alignment, both with quick and predictable success. When I re-launched, the AP wasn't working. While underway, I push the +10 or -10 buttons, the rudders move in the correct direction, but never return to center in order to stop the turn... the boat just keeps on turning. Additionally, the Autohelm compass reading seems to have little relationship to my magnetic compass (even after Heading Alignment). Also, when in Auto mode, turning the wheel now turns the boat, whereas when the unit was working properly, turning the wheel had no effect while the AP was in Auto. I tried repeating the Automatic Deviation Correction procedure, but no matter how many circles I turn (fast, slow, wide, narrow), I never get a result. I can Align Heading, but once I do, and I turn... say... 180 degrees, the Autohelm compass readout has only changed by... maybe... 40 or 50 degrees.

I've tested the fluxgate compass leads as described elsewhere on this forum with passing results. I've checked and re-checked all wiring and connections. While I bled the Hynautic pump with the wheel (and feel no air in the lines) I don't think I did - and don't know if I need to -- bleed the Raymarine Type 1 pump using the AP head unit. Regardless, doesn't seem like my problems are related to air in line anyway. I did read somewhere hear that mechanical elements in the fluxgate compass can fail and produce results similar to some of mine. Does anybody here have any advice or troubleshooting suggestions?

Thanks in advance.

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum Tizor,

Please note that it was not stated whether the autopilot was correctly indicating the rudder angle and it would be recommended that it be checked.

As the reported maximum detected deviation is so high (this value should be below 10 degrees when installed in a suitable location) and the reported heading is grossly incorrect following alignment, the problem may be rooted within the fluxgate compass (in spite of the test) or within the ST5000+ itself. As we can no longer service the ST5000+, any hope of recovering operation of the autopilot would lie replacing the fluxgate compass.

[Tizor]

Thanks very much for your timely reply. Yes, the rudder indicator bar on the AP head unit displays the rudder direction and angle accurately.

So, do I understand you correctly that it is possible that the fluxgate compass could be defective even though it has passed the impedance tests? If so, that would lead me toward thinking it is a problem with the compass, as everything on the head unit seems to work fine.

Also, I am confused as to why the wheel is no longer locked out (made ineffective) when the AP is in Auto mode. Now, even when in Auto mode, when I turn the wheel, it moves the rudders. That would lead me toward thinking the problem is with the head unit. A real dilemma here.

[Chuck - Raymarine - Moderator]

Tizor,

Q1. So, do I understand you correctly that it is possible that the fluxgate compass could be defective even though it has passed the impedance tests?
A1. Yes. The fluxgate compass resistance tests do not check for binding with the fluxgate compass.

Q2. If so, that would lead me toward thinking it is a problem with the compass, as everything on the head unit seems to work fine.
A2. Proper determination of the heading is dependent not only upon a properly functioning fluxgate compass, but also upon a properly functioning ST5000+. If after swinging and aligning the fluxgate compass, the autopilot fails to accurately report the vessel's heading when turned slowly through 360 degrees, then it would indicated a fault within one of these two component and/or an excessively strong magnetic field within the location of the fluxgate compass. As Raymarine can no longer service the ST4000/4000+/5000/5000+ autopilots, our repair centers can no longer test the ST5000+. As the fluxgate compass is a relatively inexpensive part, it would be recommended that the ST5000+ be tested with a new fluxgate compass.

Please additionally see my comment regarding excessively high deviation. Should a the new fluxgate also sense a maximum deviation greater than nine degrees, then it would be recommended that an alternate location for the fluxgate compass be found.

Q3. Also, I am confused as to why the wheel is no longer locked out (made ineffective) when the AP is in Auto mode. Now, even when in Auto mode, when I turn the wheel, it moves the rudders.
A3. A correctly function hydraulic autopilot will indeed permit the operator to turn the wheel (i.e. override the autopilot) when operating in Auto or Track mode.

[Tizor]

Chuck,

Thank you very much for responding to my questions. I have one final question on this subject... for the past two years that I've owned the boat... prior to my current issue... when in Auto mode, turning the wheel had no effect on the rudders. You could spin the steering wheel freely, endlessly, without turning the boat. I would have to hit Standby on the AP head unit in order to regain wheel steering. Sounds now like that's not normal. Do you know what may have been causing that?

Thanks again.

[Chuck - Raymarine - Moderator]

Tizor,

Q. Prior to my current issue... when in Auto mode, turning the wheel had no effect on the rudders. You could spin the steering wheel freely, endlessly, without turning the boat. I would have to hit Standby on the AP head unit in order to regain wheel steering. Sounds now like that's not normal. Do you know what may have been causing that?
A. The reported symptom may be indicative of a problematic check valve within the boat's steering system. You may want to consider having the boat's hydraulic steering system inspected/serviced by a qualified technician.

[Tizor]

I just wanted to report back and say thank you, Chuck. I replaced the fluxgate compass and all is well again. I appreciate your help. It's a very valuable service that you provide here.

[Chuck - Raymarine - Moderator]

You're welcome.