Threaded Mode | Linear Mode

KJB1999

I have the following electronics on my boat:

Raymarine E120 Classic
4kw Open Array
650 autopilot display head
S2G Course Computer with fluxgate compass
DSM300 Sonar
ST60+ Tri-data
RS 130 GPS

I replaced my original GPS sensor (112 or 120, I can't recall) with a RS130 in 2016 and it is installed using a Seatalk ng to Seatalk converter. The converter is connected to a Seatalk port on the S2G course computer and the converter is not hooked into a power source. After this installation I had no issues during the 2016 season and most of the 2017 season. The issue started at the very end of the 2017 season before the boat went into storage.

The problem is as follows: When running with all systems on (Radar included) if I press "Auto" on the control head for the autopilot the MFD immediately displays an alarm the the position fix has been lost and prompts me to acknowledge. The autopilot returns to standby immediately upon alarm triggering. The position fix is reacquired and the problem repeats itself if I attempt to re-engage the autopilot again.

I tried it with the radar in standby and got the same result except there was a bit of delay before alarm sounded and fix was lost (maybe about 5 seconds or so) versus immediately.

The batteries were all replaced at the beginning of the 2017 season and the output from the alternate on the engine the power the house bank is correct.

I attempted to duplicate the problem at my slip under the following conditions with all systems running:
Shore power connected - no issue
Shore power disconnected - no issue
Generator on and charging system - no issue

Not sure what to test next. Could it be a communication issue where the pilot wants the heading and that causes the MFD to lose it triggering the alarm which then disengages the autopilot? Any ideas would be appreciated. Thank you.