Testing speed transducer for speed through water – Complete guide

Detailed guide: How to test your Raymarine speed transducer with a multimeter for accurate speed through water.

A faulty speed transducer can cause your Raymarine instrument display to show incorrect values for speed through water. Follow this step-by-step guide to test the transducer and ensure it is working correctly.

Step-by-step: Testing the speed transducer

Perform the following procedure to check if the speed sensor is functional:

• Check the paddlewheel: Ensure that the transducer paddlewheel is free from marine growth and rotates freely on its axle.
• Turn off the instrument: Turn off the instrument display or iTC-5 before you begin.
• Disconnect cables: Disconnect the GREEN and SCREEN transducer cables from the instrument or instrument pod.
• Connect multimeter: Connect a multimeter to the GREEN and SCREEN transducer cables and set the multimeter to measure continuity or resistance.
• Rotate the paddlewheel: Slowly turn the paddlewheel by hand. The multimeter should switch between open circuit and closed circuit with each quarter turn. A full rotation should open and close the circuit four times.

Interpretation of results

If the multimeter reacts as described above, the speed sensor element in the transducer is functional. If not, the transducer is defective and should be replaced.

Tip: A properly functioning speed transducer is crucial for obtaining accurate speed through water data, which is important for navigation and performance optimization.