Trojan Boat Forum

Yesterday, my depthfinder started acting up and now just shows - - - across the display. if I use the other functions like the alarm the display works fine. I took it out of the dash and all the connections were fine, no loose wires. Going to the other end I started looking for where the transducer was. I don't recall exactly where it was on the hull but it was starboard side about 24 inches out from the keel. I'm assuming that these were factory installed since I understand they didn't core the hull in the area where there would be a thru hull fitting. I opened up various hatches and looked around but I can't find it. I'm getting nervous that it might be under the holding tank. It's too cold to go swimming to get a good measurement. Anyone have any experience locating and changing out the transducer or installing a new one?

On my 11 Meter Express, the transducer is near the mid bilge pump. As you said, it is about 24" starboard of center (from my memory). I had mine changed out when I upgraded the original depth finder.

Contacted www.dmimarine.com. They are extremely helpful. The unit I have is multifunction depth, speed, water temp, log but depth is one transducer and speed and water temp is another transducer--two holes. I just have the depth functionality transducer. Either way I need to find and probably cut a hole in the floor to get access to the transducer. Most likely the transducer is bad so I'm in for a few hundred. Or I go for a few more hundred and get a chartplotter with a multifunction transducer. Not a fan of making another hole in the hull for the added functionality of the Dart unit. Reuse the hole and fairing block if I go new.

There was another scenario where the "brain" under the dash may not be working either. All can be repaired but, do I want to sink money in to a 25+ year old device? The current large display takes up some real estate on my dash just for a depth reading. Decisions...

best not to throw good $$$ after bad.

The only issue will be changing out the 'ducer

When is your next haulout scheduled?

Otherwise, can you a new chartplotter where you can have a transom mounted transducer that can later (when you do your next haulout) be changed over to a through hull?

RWS

With the heat wave we had, no problem diving under the boat to find the transducer. No wonder I couldn't find it, it's under neath the starboard motor. The second transducer for speed and temperature is under the port motor. It has a pin in it and at one time I guess you can pull the unit out to service it. I have never had one of these transducers with a paddle wheel. I'm beginning to think spending anytime salvaging this system is a waste of time. The boat had gas motors in it originally, so when they switched to detroit diesels, servicing these transducers wasn't an issue. Any 12M owners have a good location for a new transducer?

Ours sit in the center bilge near the A/C and generator thru hulls. On the 1988 12m Sedan, that section of hull is solid glass.

Thanks! You read my mind. (is that one of the locations that is not cored?)

tcollins2 wrote: ↑Mon Jul 02, 2018 3:00 pm Thanks! You read my mind. (is that one of the locations that is not cored?)

That is correct.

Tcollins2,

My Datamarine unit was showing its age and I could barely make out the numbers. Didn't need the speed log input so I replaced it with a Sandpiper model that just shows depth. One thing I noticed was that the RCA type jack that plugs into the unit has to be tight. Otherwise it displays " ------ "

Thanks, I'll check that out too.

Confirmed 100% fiberglass in that location. Phew.

It must be the photo but that looks like a cored section . With the reflection its hard to tell

Nope, 100% fiberglass. Here’s a close up of the cut, about 1-3/8 thick.

Much better , looks good

What new equipment have you chosen to go with?

RWS