transducer troubleshooting

[rsdigennaro]

I am not getting any speed or depth readings on my ST70 display. The transducers are connected to E122xxx seatalk ng pods. The network shows the pods are connected, but no readings. How do I troubleshoot the transducers?

[Steve - Raymarine - Moderator]

There isn't a transducer test for a depth transducer, the only test is getting another transducer, connecting to the POD and putting the transducer over the side of the boat. If the system starts to read it will confirm a bad depth transducer.

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.