HELP, Garmin GPS, Autopilot interface problem

[Joe]

I have a Garmin 126/128 GPS. I’m trying to hook it up to my ST4000 Wheel Drive Autopilot.I’ve followed the wire diagram in the owner’s manual of the GPS, NMEA out (blue wire) NMEA in (brown wire). On the back of the control head of the autopilot, it has a NMEA plus terminal and a NMEA minus terminal. I connected the NMEA out, from the GPS to the NMEA plus on the control head and the NMEA in, of the GPS to the NMEA minus on the control head as discribed in the owner’s manual for the autopilot. I tried the interface on the GPS set to NONE/NMEA or NMEA/NMEA 0183 version 1.5 or 0182, or 180. Following the procedure in the autopilot owner’s manual, the head flashes “WPT PORT, WPT STARBOARD but will not track to the selected waypoint. Can anyone give me assistance with my dilemma? I’ve checked the archives but couldn’t find anything that helped. One did mention to hook up the NMEA minus to ground but it was not clear if it was the one from the GPS or the terminal on the autopilot.Thanks All!Joe

 

[Jose Venegas]

The terminal from the autopilot

In my set up, (Garming 162 + B&G autopilot) I had to connect NMEA out of the GPS to the NMEA (+) of autopilot the NMEA (-) of the autopiloto ground. This was also the case for the NMEA inputs to the VHF radio, and the Radar. I had to leave the NMEA (-) from the GPS floating, or connected to the COM cable of the computer interface. Good luck

 

[Mike DiMario]

Confirmation

Joe,It sounds like all is okay. I think I may know what it is. THe autopilot has a safety feature. It will not make the turn to port or starboard unitl you confirm that is is clear by hitting "Track" one more time. It is in your autopilot book.The fact that you are getting the signal "Wpt Strd" or Port is a sign that all is well!good luck,Mike DiMario

 

[Joe]

THANKS FOLKS!

Seems like Mike hit the nail on the head. I didn’t give it a sea trial yet but, in my slip last night I tried it again and it displayed all the correct information on the AP head. I may be going out this evening for a real test run.Thanks again, Joe