Re: trolling motor wiring diagrams
Silvertip is correct that the current system can work if you use the correct leads on the receptacle. To each his own. I personally would remove it. 1, it is confusing, it confused you and likely would the next owner. 2, it requires two breakers, one on each positive lead near the battery to be safe. Do you have that now? 3, it requires additional wire connections at the switch which subjects it to more corrosion and more resistance. 4, your not going to buy another new 12/24 volt motor so the switch is never going serve a purpose again.
I personally would wire the two spare wires to my crank battery and replace the switch with a 12 volt receptacle to charge my phone, run a spotlight, or something like that.
What ever works best for your needs.