All you need is the cable. Connect one end to the NMEA 2000 bus that goes to your Lowrance sonar and LGC-2000 sonar module and the other to the white connector with the blue and white wire in your engine. They make Tees that allow you to do this. Maybe this will help:

LowranceNet/NMEA2000 bus:

Terminator----tee-----------------tee------------------tee-----Terminator
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Lowrance LGC 2000 Yamaha
Sonar GPS Engine


After it is connected, go into second menu and look under 'Bus Setup' and you should see your engine (engine ignition must be on). Select your engine and you will see all the data it is sending. You can then overlay the data you want on your sonar/GPS pages. Fuel rate and engine hours are very handy.

Let me know if you have any more questions.