I purchased a Mercmonitor from European Marine and wanting to install today! I have a couple questions! It came with a external power harness, do I need to hook it up? I will be connecting it to my NMEA 2000 network! If I don’t install the harness, do I need to take that fuse out? If I do install it, do I need unhook whatever is powering the network currently? (I believe it’s powered through my lowrance)!