Troubleshooting Raymarine ST-60 speed

[Quickstep192]

The speed on my ST-60 died unexpectedly. I've done the rudimentary troubleshooting steps; pulled the paddlewheel and spun it by hand to make sure it wasn't stuck and checked and re-made all of the connections. Since I installed it, I know there are no splices. The head powers up and seems otherwise fine, but never registers more than a few tenths of a knot. What are my next steps? Is there a way to measure the output of the paddlewheel sender with a VOM to determine if it's working?

[Faster]

When you spin it by hand do you get a speed readout? If so then it's related to being in 'position' in the thruhull. When you spin it did you feel a 'magnetic attraction' to the paddle blade? Normally at least one paddle will have a magnetic slug that the transducer detects ( and counts the pulse rate for speed) Maybe that fell out?

If not, and your sure there's no wiring problem then it's gotta be in the unit itself....

[wwilson]

Quick,

If you haven't posted that question here:

https://raymarine.custhelp.com/cgi-b...1SYXkyMDA2ISM*

then you should. They are very responsive and helpful.

Here is one of their FAQ responses that is related:


Testing the Speed Sensor:

Verify that the transducer’s paddle wheel is free of marine growth and rotates freely on its shaft
Power down the instrument
Disconnect the GREEN and SHIELD transducer leads from the instrument display or instrument pod.
Connect a multimeter to the GREEN and SHIELD transducer leads and configure the multimeter to measure continuity or resistance.
Slowly rotate the transducer paddle wheel by hand. Note that as the paddlewheel is rotated, the multimeter should alternate between an open circuit and a closed circuit with each quarter turn. As such one complete revolution of the paddle wheel should open and close the circuit four times.

Should the multimeter respond as indicated above, then the speed sensor element of the transducer would be deemed functional. If not, then the transducer has failed and should be replaced.


(Sorry for that ugly URL)

Wayne