General Info: airmar transducer not working

[SSD]

I have a Garmin chart plotter and a airmar 20-633-01 try multi sensor. The depth appears to be working but the temperature reads 130 degrees. The paddle wheel is clean and rotates fine but no speed is displayed. Looking to see how to test?

[b_ohare]

Originally Posted by SSD

I have a Garmin chart plotter and a airmar 20-633-01 try multi sensor. The depth appears to be working but the temperature reads 130 degrees. The paddle wheel is clean and rotates fine but no speed is displayed. Looking to see how to test?

I've been fighting with a similar issue on my Airmar 810. Depth and temperature are fine but boat speed remains at 0. If yours doesn't even show 0 as boat speed (e.g., it shows a dashed line or it's blank), it might be a configuration issue in your chart plotter (e.g., make sure the chart plotter is using the proper device to measure boat speed). If it shows 0, you should be able to remove it, blow on the paddle wheel, and see if it turns and shows speed. (I was advised if you can't turn it by simply blowing on it, it likely needs to be cleaned; spinning with your finger isn't a good enough test.) Other potential issues could be it's not pressed down completely in the thru-hull, it's not facing the correct direction (the arrow on top should face forward toward the bow), or there's something on the bottom of your hull blocking flow (i.e., it needs to be scraped).

In my case (and I'm on my second one as the first one was replaced under warranty because Navico thought no boat speed meant it was just a defective transducer), I'm told the only other possibility is the thru-hull fitting is somehow bad. But the only way to check that is through a haul-out.

[SSD]

Yes bottom is clean and wheel spins free. It is displaying 0 as boat speed. The other crazy thing is the water temp displays 130 degrees, the temperature never changes. I am hauling next week so I will take a better look then. Thanks

[GordMay]

Greetings and welcome aboard the CF, SSD.

See “Testing Knot-Log Speed Instruments”
➥ https://www.cruisersforum.com/forums...tml#post164512

[Martkimwat]

I'm not familiar with the Garmin setup but since pretty much all sensor/transducers are made by Airmar then badge engineered for the various plotter manufactures, they will all work the same with only the end fittings being different. Raymarine have a testing program for the DST800/810 Tridata transducer on their website, may even be on the Airmar website too which you can download, only needs a volt meter, an 8 volt power source (not 9v)- I bought a little buck converter off Ebay for a couple of pounds- and the program on how to test the transducer. simples.

[GordMay]

Originally Posted by Martkimwat

.... Raymarine have a testing program for the DST800/810 Tridata transducer on their website, may even be on the Airmar website too which you can download ...

Link?

[Martkimwat]

Originally Posted by GordMay

Link?

Took me about thirty seconds to find this and I'm not a techie!

https://raymarine.custhelp.com/app/a...ting/related/1

[GordMay]

Originally Posted by Martkimwat

Took me about thirty seconds to find this and I'm not a techie!
https://raymarine.custhelp.com/app/a...ting/related/1

Good on ya, and thanx!

[SSD]

Thanks everyone for the help I will take the advice and let you know how I make out.

[Dr. D]

SSD: What happened? I'm very interested as the other day I was sailing and the speed reading was fine. Then it was flaky. Then it was zero and stayed that way.

BTW, where can one purchase the paddle wheel replacement kit? West Marine doesn't carry it, nor does Defender.

[Franziska]

Originally Posted by Dr. D

SSD: What happened? I'm very interested as the other day I was sailing and the speed reading was fine. Then it was flaky. Then it was zero and stayed that way.



BTW, where can one purchase the paddle wheel replacement kit? West Marine doesn't carry it, nor does Defender.

I just bought a paddle wheel replacement kit for our P66. Depth and temperature were working, but speed not.
Someone suggested a new paddle wheel assembly.
Ours turned freely and was clean, but I thought might be worth a try.

It did not get us in water speed back. So in our case the replacement was not worth it.

Next step, we will need to check the cable and plugs again...

[Dr. D]

Let us know what happens. If I get mine working I will post.

[SSD]

I ended up purchasing a new Airmar sensor from Hodges Marine in FL. They had beat price and I have had great luck ordering thru them before. They also have the rebuild kit you were looking for.

[Dr. D]

Thanks!

[Dr. D]

I got to my boat yesterday afternoon. Spent a good amount of time thoroughly cleaning the transducer, including removing the paddle wheel. It did have some mud (or something) on the sides. Reassembled and installed. This morning I went sailing. I got a boat speed reading from the transducer! For about 45 minutes, then back to "0".

I guess I will try the paddle wheel replacement kit route first. I'd rather pay $22 than a whole lot more, though what makes me hope the kit works is the alternative. To replace the transducer I would need to trace the wire from the existing one to where it is plugged into the NEMA 2000 network. With all wires in conduits, that will be a major chore.