I have a MotorGuide with built in transducer. It was setup for a Garmin when I got the boat. I just got a Lowrance X510C for it. I purchaced the 7 pin Blue/Gray adapter cable from Cabelas at the same time. The end for the unit is correct but the end that plugs in to my trolling motor is not. The one coming from the trolling motor has a screw type connection. The adapter cable has a tab on each side that looks like it should fit over and snap into place. The pin orientation looks correct but no way to get them to slide together. Any one else seen this? Or have an idea of what I need to do next. Maybe another fitting I am missing to join these together.