[C320-list] Testing/Replacing Knotmeter Transducer

[Joel Krauska]

My knot meter isn't reading.   I've got Raymarine ST60 instruments.

The boat show Raymarine rep said to double check the connectors inside the
nav pod.  They look ok, I've reseated them, I'm still not getting any
readings.

I've spun the thing slowly for about 60s trying to get /any/ reading, and
Max Speed still reads 0.

I'm armed with a handful of cheat sheets detailing how to test/check a
knotmeter transducer, and I plan to do a bit of that. (make sure instrument
is suppling 12V, make sure spinning the wheel causes square wave up/downs
on the other lines)

If that all fails, I imagine I'll want to replace the transducer.  For the
life of me, I can't make out a model number.

Ideally I can the the same inner sleeve and not have to replace  the entire
thru-hull, but that means I want to find a perfect match.

Has anyone been down this road?  Any guidance?

Cheers,

Joel
Grace #802