Depth Sounder

Recently I have started having depth sounder issues where I get no depth showing on my Garmin 740S at start up. After about an hour I will start getting accurate readings for awhile (15-30 minutes). Then it will stick on a depth and start flashing that depth for a random period of time. It then may work properly for a few minutes. I had a diver clean the bottom thinking that the transducer may be fouled but that did not help. I could understand if it just wouldn't work but being an intermittent thing is a real puzzler to me. Anyone ever have this problem?

evansrr said:

Recently I have started having depth sounder issues where I get no depth showing on my Garmin 740S at start up. After about an hour I will start getting accurate readings for awhile (15-30 minutes). Then it will stick on a depth and start flashing that depth for a random period of time. It then may work properly for a few minutes. I had a diver clean the bottom thinking that the transducer may be fouled but that did not help. I could understand if it just wouldn't work but being an intermittent thing is a real puzzler to me. Anyone ever have this problem?

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Sorry, I have no answer for that issue, but had the same thing happen on my Lowrance GPS/Sounder combo after one rather long leg. The unit is 12 years old. Things do sometimes break down. Some electrical connection somewhere cracks...? Who knows..? It has never worked properly since, no matter what I do, but the GPS does. So, as I quite like not having to split the screen anyway, I just leave it in GPS full screen and I installed another two simpler, sonar-only sounders, one up and one down, so I now have two dedicated new sounders, and the old original, came-with-the-boat Seafarer, which still works, as an extra back-up. This was a cheaper option than going to a new GPS/sonar combination unit, which are now high definition, bigger, and cost more.

I now assume it has just broken. Something my generation are, or rather, were, highly familiar with, but I suspect we are now so used to incredible reliability in most modern gear, being used now to things that seem to work forever, one is surprised when something just stops working. When you sometimes hear the phrase from someone, "ah, they don't make them now like they used to"...insinuating poorer quality, my immediate thought is, "yes, and thank goodness for that". But sometimes they actually do just fail...

One of my 2 Garmin transducers shoots thru the hull(long story, I was calling them "Vermin" for a while) but it takes longer to "find" the bottom, maybe 2 minutes, then it`s fine. The conventional thru hull one occasionally "flashes" a reading, usually way off what it should be, then resumes proper readings. Happens more often when close to antifoul time, suggesting fouled transducer. Not sure that helps your problem.

Are you running a nmea 2000 transducer or nmea 0183? The 2000 use a plug in connector; the 0183 have individual wires you connect to the 740 harness (usually at a terminal block).

Ted

My Garmin 3210 has been acted up on depth.The same thing that evansrr's is doing . Then it quit and for the last 6 months it hasn't shown any depth reading at all .

O C Diver said:

Are you running a nmea 2000 transducer or nmea 0183? The 2000 use a plug in connector; the 0183 have individual wires you connect to the 740 harness (usually at a terminal block).

Ted

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It would be the 0183. I'm guessing that based on the intermittency of the issue that the transducer is just wearing out and there's no simple fix.

evansrr said:

It would be the 0183. I'm guessing that based on the intermittency of the issue that the transducer is just wearing out and there's no simple fix.

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That unit should be able to use a 2000 transducer. Might be worth buying one, hanging it over the side of the boat, plugging it into the 740, and seeing if it solves your problem. If no, return the transducer. If yes, install it at your next haulout.

Ted

Our depth sounder was getting progressively worse, until it wasn't reading anything deeper than about sixty feet. While checking connections at the back of the display unit (moving wires around to have a good look) it worked perfectly for a second, then returned to its goofy, insensitive state.

Turns out it was simple fix...draping the transducer cable over a small object just before the cable enters the depth sounder display unit corrected whatever interference it was experiencing, and it now works perfectly again.

Hopefully your problem will have an equally simple (inexpensive) fix

MurrayM said:

Our depth sounder was getting progressively worse, until it wasn't reading anything deeper than about sixty feet. While checking connections at the back of the display unit (moving wires around to have a good look) it worked perfectly for a second, then returned to its goofy, insensitive state.

Turns out it was simple fix...draping the transducer cable over a small object just before the cable enters the depth sounder display unit corrected whatever interference it was experiencing, and it now works perfectly again.

Hopefully your problem will have an equally simple (inexpensive) fix

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Maybe a broken wire in the cable that makes contact when the cable is bent to a different position. Have seen that where the wire wasn't soldered to the connector pin and bending it made the wire touch the pin.

Ted

Transducers

BruceK said:

One of my 2 Garmin transducers shoots thru the hull(long story, I was calling them "Vermin" for a while) but it takes longer to "find" the bottom, maybe 2 minutes, then it`s fine. The conventional thru hull one occasionally "flashes" a reading, usually way off what it should be, then resumes proper readings. Happens more often when close to antifoul time, suggesting fouled transducer. Not sure that helps your problem.

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I have a Simrad Go 7 and a new Garmin. I want to mount the transducers internally so they work through the bottom of the hull of my Grand Banks 36. Any suggestions?

Bryant said:

I have a Simrad Go 7 and a new Garmin. I want to mount the transducers internally so they work through the bottom of the hull of my Grand Banks 36. Any suggestions?

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Measure the transducer that came with the new sounder. Buy a short length of ABS pipe (black, cheap) to fit the TD inside. Measure the angle of the hull from vertical. Cut the pipe to stand vertically with a good fit to the hull. Epoxy the pipe to the hull. insert the TD. top up with a light oil. I used Telus 10, as I had some for my hydraulic steering. That was now many years ago. I have had no issues whatsoever with that installation.

Bryant, koliver`s post #11 above is essentially what I would have said.
Some suggestions. You can use the transom mount transducer often included in the package. It should be vertically mounted to point straight down, a small level will be useful for checking this. I set mine in silicon sealant, as suggested by Garmin.