[DG] [DG] Autohelm 4000 interface w Garmin GPS48

[Derek - Raymarine - Moderator]

Hi John,

Which model of AUtohelm 4000 are you referring to? ST4000 or the older Autohelm 4000?

To get NMEA0183 data out of the Garmin 4 pin plug to connect to an autopilot, you will need to use the Brown data out connection as the Data out +ve and the power supply 0 volts connection as the common Data out -ve. It sounds like this model from Garmin does not use the conventional NMEA0183 twin wire connection, just making use of the power supply -ve as data out -ve instead.
regards
Derek