Topic: Troubleshooting 997cSI, no dpeth on plane

[FishPig]

Have an older 997cSI with Y cable and 2 transducers - the SI 'ducer mounted on the transom and a round one epoxied into the hull. I no longer get any readings while on plane, and it takes a couple minutes or so for it to start reading again once off plane. Everything else works perfectly. Cables appear to be properly connected at the Y and the unit (if they weren't I suppose it wouldn't even work at slow speed). The round' 'ducer was already replaced once before. I have to literally tear the back end of the boat apart to get at it, so I tried to be VERY careful and epoxy it in well the last time. But my guess is that it must have still come loose so only the SI 'ducer is working.

Best way to trouble shoot? Something to try without tearing the boat apart?

[rnvinc]

Add water in the bilge enough to cover the xducer and test - this may determine if the epoxy has failed by filling air voids between the xducer housing and the epoxy  ...

Did the bilge xducer work correctly before now??

Rickie

[FishPig]

Been on vacation, just getting back to this.....

So do I do this while the boat is in the water I presume? I can't think of how I would "test" it otherwise unless I can drive the boat on plane. How would I get water into the boat - bring a handheld pump or bucket?

[rnvinc]

Been on vacation, just getting back to this.....

So do I do this while the boat is in the water I presume? I can't think of how I would "test" it otherwise unless I can drive the boat on plane. How would I get water into the boat - bring a handheld pump or bucket?

Yes test on the water and bring a bucket to get water into the bilge  ...

Rickie

[FishPig]

Ok, here's the story.

I disconnected the Y cable and tried each transducer individually. The thru-hull did nothing. The SI operated correctly at slow speed but lost depth once getting on plane (as expected). Then I reconnected the thru-hull 'ducer and used a pump to fill the back/bottom of the boat with water as suggested. Still nothing. So that transducer is obviously the culprit but it probably isn't an air problem. So.....

I can tear the back end of the boat apart (quite literally) and try installing a new thru-hull transducer for the 3rd time OR what about mounting an external transom mount style? (I think it might be an xtm-9-20?) Shouldn't that read on plane also? Does it work with the Y cable like the thru-hull style?

I was SUPER careful when I installed the thru-hull type last time because I didn't want to ever have to mess with it again. I really can't imagine doing it any different/better than I already have. Or maybe break down and bring it to an experience marine dealer/rigger in the off-season?

[rnvinc]

I think your troubleshooting has been concise.. and correct  ...
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The XNT 9 20 would be the transom mount 2d xducer version that will work with the Y cable  ...
https://www.humminbird.com/Products/XNT-9-20/

Some say that the transom mounted 2d is more reliable than the shoot thru for consistent high speed depth readings  ...

Rickie

[FishPig]

I purchased an XNT 9 20. Before going through the whole install, I connected it to the unit and powered it up (after disconnecting the SI transducer of course). It is not recognized by the unit.

Could this be the wrong transducer? Does the unit only recognize it when its connected to a Y cable and you get on plane? It seems like it would recognize it as a stand-alone transducer, but maybe not. I'd sure like to know this is gonna work before I drill more holes in he boat, run the cable, etc.

[Bob B]

Unless it is the XNT 9 20 T, there is no temp sensor.  I think the unit doesn't think there is a connected transducer if it doesn't see the temp sensor.
When the Y cable is connected, it get the temp from the SI transducer.

[rnvinc]

Like Bob mentions the unit won't recognize any xducer connected without a temp probe  ...

Power on the unit and press the Menu button as soon as the HB splash screen appears  ...

You will then get a popup where you can force the unit into Normal operation mode to test the XNT 9 20  ...
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And also as Bob mentions temp will come from the SI xducer when the AS SIDBY Cable is used  ...

Rickie

[FishPig]

Sorry if I didn't mention it, but the one I bought DOES have temp. So how does that change your replies?

[Bob B]

Try changing the connected transducer to dual beam and see if it recognizes it.