So I bought a blueseas 3 position switch to wire 24 volts to one side and the other side 36 volts. I have 2 AGM batteries and 1 lithium 36 volt battery. I have a Garmin Force trolling motor so it can run on either 24 or 36 volts and I will only be using the 24 volt set up when I manage to kill the 36 volt lithium battery. What gauge wire should I use? I have either 8 or 6 coming from the bow into my bilge area and I was thinking of using 6 to go from each battery into the switch. Any body got any recommendations? Also the switch only has 3 posts, I'm assuming for 3 + wires, can I just hook all the ground wires into the negative wire that comes from the bow? Again, any help or input is appreciated. I don't want to catch my boat on fire.