ITC-5 speed calibration failure

[cstotland]

I just replaced my A22154 triducer. The initial symptom was speed quit. Temp and depth worked fine. Speed LED on ITC-5 blinked, never went on hard. Had been working solid for two years. Replaced the sensor with a new-in-box unit (S/N 3762703).

Before connecting the new one, I cut off all but ten feet of wire from the old sensor, crimped on some 1/8" lugs, and reconnected the original to see if it was possibly the cable that had gone bad. (two year old install). To my surprise, everything came up hard lit, but the speed display was indicating about 40 kts speed. Boat is in slip. Hard to hit 40 in a sailboat there or anywhere. Thought, "OK, so it's really messed up". So, I disconnected it, and hooked up the new one. The new one came up at 80kts (bounces around a bit...70...75...90...80, etc.). I used the I70 (which previously didn't "see" the old speed xducer at all when it quit), reset to factory, and tried the calibration. I am able to go "up" to a bit over 90Kts, and down to about 48kts. At those points the up/down arrows disappear, so it appears the calibration function is operating correctly, and it's the auto-zero that isn't.

anything else I can do besides send the ITC-5 back for repair?

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum cstotland,

Before sending the iTC-5 to Raymarine's Product Repair Center, it is recommended that the speed transducer's bare lead be shifted from the speed/temp terminals to the black depth transducer terminal and that the system then be tested. Should the problem persist when connected in this manner, then the iTC-5 should be sent to Raymarine’s Product Repair Center to be bench checked / serviced.

[cstotland]

Chuck,

The instructions for the Triducer indicate the bare wire lead should be connected to the depth drain connection, not the speed/temp. I connected as recommended by the transducer directions.

"When connecting a DST800 to an iTC-5, only one screen connection is required. This must be made to the Depth terminal on the iTC-5. In this configuration, the screen on the Speed/Temp terminal must remain disconnected."

Except...Turns out it was my bad....I had the shield and black wires reversed. I'd installed the black tube included with the fittings over the drain wire and mixed the two up. Seems OK now. Sorry for the false alarm.

BTW, the Speed LED lights hard for several seconds before beginning to flash

[Chuck - Raymarine - Moderator]

Cary,

Thanks for the feedback. I had failed to initially note that the transducer was a DST800 rather than separate depth and speed/temp transducers. I'm glad to learn that all is now operational.