I have learned a lot about my HDS 7 GEN 2 from the best forum on the web. At the time I installed my unit, I did not add structure scan to my HDS 7. I am thinking about adding it now. I sold the x510 that I had and changed just the head unit of my HDS 7. I have transducers at each end e/w a toggle switch. I am thinking of adding structure scan now . Since I kept the old power cord from my previous unit. Will I now need a cut off switch in order to cut off the structure scan? If so, what do I need. Where can I get one?I know canepole knows this. By the way I liked your transducer shoe.I will be using something similar as I want to mount to the trolling motor and want to be able to scan an area. Thanks for any input or suggestions