Autohelm Depth Transducer Access

[Gubbo]

Hello,

Can someone assist me by advising how I can access the oil bath in my in-hull transducer.

The unit is an Autohelm ST30 and I believe the transducer would be a Z117 but unfortunately can't find any more details of it on-line. The unit is just at fingertip reach at the bottom of the bilge but is too tight to move easily. I'll have to make a tool to release it so would like to know whether its a twist or bayonet movement I need.

I want to check the oil as I have the flashing units fault whilst the depth reading remains at zero. I have researched this forum for the many other posts on this subject but struggle to find any that detail a successful conclusion, although several suggest the oil level is a good start. The transducer itself is "ticking".

many thanks

 

[Cardo]

That looks a lot like the Airmar P79 I just installed in our boat. If it's the same mechanism, it's a simple slight turn anti-clockwise to unlock and then lift. There's a couple of small tabs that lock into place when you turn it clockwise. Not a thread.
On ours, there's an O ring that creates a seal. The instructions advised putting Vaseline on it to assist with the sliding motion (eh eh). If there's no Vaseline on yours or it has gone dry, it may have become stiff (Oh dear!).

Link to installation instructions for P79 - http://www.airmartechnology.com/uploads/InstallGuide/17-217-01.pdf

 

[Gubbo]

Thanks Cardo, theres some good advice on the link.

Only snag is that mine doesnt have any knurling or obvious separation joint so even now beginning to wonder if it contains fluid at all.

Has anyone else got the same model? For reference its the original fitment in a 1995 cornish crabber.

Thanks

 

[LeonF]

Gubbo I have exactly the same problem, 'metres' flashing and no reading. Handbook says transducer or connector problem. The rest of the display is fine. I've checked the transducer cable visually and as far as I can tell it's fine, but no clicking from the transducer, though I have been told this isn't strictly necessary.
I've remade the spade connections into the control head, cleaned off the terminals in the head, and still no luck.
My boat is a '96 model, so I believe we must have the same transducer, and I don't think I have an oil bath type either. I do have the original handbook, also available on line from the Raymarine website. I believe it's mounted from the outside of the hull onto Sikaflex or similar and then the nut tightens it from the inside. Boat is on the water, so I have no easy solution if I need a new transducer (I mean cheap!).

 

[LeonF]

Just done a search and found some interesting posts. Is your boat ashore ? Could be too shallow to register. Also some posts re voltage levels. Mine receives it's voltage via a Seatalk cable from the Autopilot instrument head, and will check this. It could be those connectors which need cleaning.

 

[Keith-i]

I may be a bit late on the scene to help you, but we have the same puck in our boat. I don't think it contains oil. It is a P76 style.