Mystery transducer

[Seamonk]

There are 3 transducers on my (new to me) boat, a Fisher 30. The one connected to the Clipper readout always reads 1.6m. The cables of the other two get lost in the rats nest of cables and wires in the engine room, but don’t seem to connect to anything. One of them is somewhat distinctive. Does anyone recognize this transducer?

I’d like to think one of the three might someday tell me how much water is under me.

 

[Refueler]

Have you pulled it and looked at 'other end' ??
(Blanking plug handy of course !)

Just a thought ... nearly all transducers I've seen with a handle - are speed logs ... handle not only helps to 'pull' it out - but in turning it to align for speed readout.

Regards the Clipper readout ... check the hull offset - it may be that the 1.6m is the offset put in by previous owner ... and in reality - the sounder is not getting through the hull (I assume its an in-hull mounting - not through hull ?) If in hull - then its likely that the hull location chosen has something blocking the signal ... I would suggest pulling that sounder and testing other areas of hull to find where it works.

 

[LittleSister]

I suspect that the failure of the Clipper is more likely to be a wiring or connecter problem, or not solidly connected to the hull by the oil in the oil bath (or glue to the hull), or less likely a transducer failure, than a hull obstruction preventing it working.

Carefully inspect the transducer cable and the connector.

To check the transducer is working remove it from its oil bath (assuming internally mounted) and dangle is over the side to check the transducer is working.

To check the oil bath (assuming you have one), see the installation instructions in the Clipper manual.

 

[Refueler]

I suspect that the failure of the Clipper is more likely to be a wiring or connecter problem, or not solidly connected to the hull by the oil in the oil bath (or glue to the hull), or less likely a transducer failure, than a hull obstruction preventing it working.

Carefully inspect the transducer cable and the connector.

To check the transducer is working remove it from its oil bath (assuming internally mounted) and dangle is over the side to check the transducer is working.

To check the oil bath (assuming you have one), see the installation instructions in the Clipper manual.

It would be highly unlikely to show 1.6m reading if it was faulty wiring ... a clipper transducer is Co-Ax cable I believe ....

I agree that a real test is to stick tranducer overside ... but usually there is not enough cable to do this .. and OP mention that cables are a rats nest etc.

 

[Seamonk]

Have you pulled it and looked at 'other end' ??
(Blanking plug handy of course !)

Just a thought ... nearly all transducers I've seen with a handle - are speed logs ... handle not only helps to 'pull' it out - but in turning it to align for speed readout.

Regards the Clipper readout ... check the hull offset - it may be that the 1.6m is the offset put in by previous owner ... and in reality - the sounder is not getting through the hull (I assume its an in-hull mounting - not through hull ?) If in hull - then its likely that the hull location chosen has something blocking the signal ... I would suggest pulling that sounder and testing other areas of hull to find where it works.

Yes. Likely to be an impeller. I’m hauling out in a couple of days so I can check it then.

 

[Seamonk]

Turned out to be a VDO speed log with a missing paddle wheel. But with no instrument to display the data. Just a (plugged) hole in the boat.

Guess I’ll try to find a transducer that can feed data to the Raymarine chartplotter? Any suggestions?

 

[Refueler]

Problem is to seal whatever you put in that through hull ... probably why previous owner left the speed log there.

Often the diameter of sounder and speed logs are different ... so again back to how do you seal whatever you put in there.

Seems strange to have a speed log installed - but no display ??

You say you have 3 transducers .... ?? How many displays ? May sound daft - but are you sure the tranducers are plugged into the correct displays ?? Maybe I'm wrong - but your posts say to me that the speed log was plugged into the sounder display ??

 

[Bodach na mara]

You're not alone Seamonk. Everyone who has bought a boat that has been previously owned can relate to these problems. I have had my current boat for 9 years now and keep find new things in the wiring that confuse me. Like you, my Clipper depth displays a constant reading of 1.6 metres. Most of the time. But some days it displays varying readings, but none of them correct. It has only started doing this since last September. For the previous 8 1/2 years it worked well, although it lost the bottom at about 50 metres, beyond which I refer to the chartplotter. I have tried to trace the wiring to link the Clipper to a transducer, but after it leaves the meter it goes through the hatch garage and then through a ventilator below the deck and into the space between ceiling and deck. Where it gets lost. Now I know which transducer feeds the chartplotter (because I installed that myself) and I know that there must be another two, one for the Clipper and one for Garmin instrument that should display depth and doesn't, but I can find only one. And tracing the capital from it gets me nowhere because after a few inches it enters a conduit with several other cables. The conduit seems to end up in the cockpit locker but there is a different number of cables at that end.
So I am really hoping that someone has found out why NASA Clipper depth meters fail with the display showing 1.6 metres!

 

[Refueler]

Previous owner of the 38 I have ... the yard did all the repairs / maintenance etc.

Example :

Fwd dual nav light did not work ... so traced wires into fwd bunk area ... a white and black leads. Aft behind the switch panel - looked for white and black leads ... mmmmmm loads of white ... ;loads of black .... but which ones ?
Turns out that behind the woodwork - the black connects to a white lead .. so in fact - its two white leads to identify ... took ages testing each white lead till we hit the right ones ...

One day I will try and sort it all out .....

 

[Bodach na mara]

And the best of luck with that Refueller. I don't want to put you off but I've been saying that for the last 9 years!

I have found out something today however. The transducer that I have been looking at is nothing like the one in the picture of a system advertised by Marine Super Store. So that one must be linked to the Garmin instrument.

 

[Refueler]

You can get new impellors ... just needs a new axle pin ..... maybe your old unit can be cleaned up and put back to use with new impellor ??

 

[Seamonk]

Previous owner of the 38 I have ... the yard did all the repairs / maintenance etc.

Example :

Fwd dual nav light did not work ... so traced wires into fwd bunk area ... a white and black leads. Aft behind the switch panel - looked for white and black leads ... mmmmmm loads of white ... ;loads of black .... but which ones ?
Turns out that behind the woodwork - the black connects to a white lead .. so in fact - its two white leads to identify ... took ages testing each white lead till we hit the right ones ...

One day I will try and sort it all out .....

I’ve rewired 3 boats - Tulip is #4 - and looking at your photo just makes me cringe. Every time I see such a mess I think “I’ll sort it out” and every time I end up ripping out everything and starting over from scratch.

 

[Refueler]

I’ve rewired 3 boats - Tulip is #4 - and looking at your photo just makes me cringe. Every time I see such a mess I think “I’ll sort it out” and every time I end up ripping out everything and starting over from scratch.

The biggest problem is that the boat had equipment changed .. and the yard did not remove old wiring. Second - that it all dissapears behind very nicely fitted wood panelling ...

I'm afraid to start removing the panels - in case they don't go back correctly again .. not all fasteners are visible .. with a lot of hidden fasteners.

 

[Seamonk]

Took me a while, but I found the instrument attached to the “mystery transducer”. There was an old, no longer used, engine hour meter installed in a bulkhead. When I finally removed it I noticed that it was a VDO instrument. And sure enough it had a distance (not speed) read out.

Now the question is: how many engine hours were registered on the original Volvo hour meter before the VDO replaced it? It’s apparently the original engine from 1970!