Electrical screw up

[Tebone]

I put the battery back in my 4 year old yamaha 65 hp with 704 remote control and didn’t see the LV red cable and put the negative on the positive. Starting up and fried the ignition and some wires under my console. Replaced the ignition and cut out the bad wires and replaced. Inspected the other wire runs and they appear to be in good shape. Put a new battery in but am not getting any power to the controls. Called an electrician and he thinks I may have fried the ground. The red was never hooked up. He said with out the ground I would get no power. The fuses I can find appear to be fine. Any suggestions