Correct.....autosence not needed. You need to make the cable with the pinout Josh7 describes. The adapter cable is made from 2 deutsch DTM04-12PA connectors. The adapter goes from the NavII main cable to the same plug on the ez-pilot harness that would normally plug into the back of the display. The wiring digram makes it look like the cable is short but it actually needs to be fairly long. Cut a piece of 4 wire trailer wire or something comparable 10' then you can trim back as needed. I think my final length was 8'. (it needs to be that long to neatly tie wrap to the main cable for neat install) The IMD 600 will be unplugged from the harness and that plug will not be used. The 750 firmware will need to be version 7.50 or higher. The navII will need to be version 13.0 or higher You will also need to upload the vehicle data base for your tractor to your Nav. While the 750 is updated with a flash drive, the Nav update and the vdb (vehicle data base file) will have to be done with a laptop and Flashloader 200 program. You can find the Flashloader 200 program, all firmware updates and Vehicle Database files at http://www.greenfieldag.com on their Trimble Download Page. You will need an cheap 9 pin serial cable to connect your laptop to the Nav2 to update and download the vdb file. Be sure laptop has 9 pin plug.