Erratic output from ACU 400

[Chuck - Raymarine - Moderator]

Andy,

Please click here to view a FAQ addressing this subject. Given the problem reported with Speed (Through Water (STW)), it would be recommended that the autopilot be configured to use GPS SOG rather than STW until the STW problem has been address. Before doing so, should the EV-1 autopilot software have been updated from v1.11 or earlier software and should a Pilot Factory Reset have not been commanded, then it would also be recommended that this action, re-execution of the dockside wizard, and re-execution of the deviation / handling cruise be performed. Please click here to view a FAQ addressing this subject.

Given that the iTC-5 has been replaced, the Speed / Temp transducer / transducer insert may have suffered a failure. In order for the iTC-5 to properly sense STW, both the speed and temperature sensing elements of the speed / temp transducer / transducer insert must be functioning properly. Should the sensed temperature be wildly inaccurate (differ by tens or even hundreds of degrees), then the iTC-5 will interpret this condition as one in which the iTC-5 has not been interfaced to a speed / temp transducer / transducer insert. Additionally, STW must be calibrated via the i70/i70S MFID.
The following FAQs may be of assistance in testing an instrument speed/temp transducer:
- Testing an instrument speed through water transducer / transducer insert featuring a paddlewheel
- Testing an instrument water temperature thermistor
As we desire to restrict threads to a single subject within the Raymarine Forum, should additional guidance on correcting the STW or wind problems be required, then please create a separate threads within this Forum to be dedicated to these issues.