The tech support guys at Airmar ate great , give them a call. I have a b744v that was already in the boat when I got it. It is not nmea 2000
compatible. Needs to be plugged in yo the correct sounder unit. And there are different models of each unit , that are sounder specific . Mine was ordered for a lawrance unit , and I bought all garmin
stuff. The tech guys at airmar emailed me a sketch of what color wires had to be connected to what color wires to make it all work. The only thing I lost
in the conversion was the water
temp wasn't compatible between the garmin
and the lawrance units. But the fish
finder , depth
finder , and speed worked just fine.