3 prong trolling plug

[wiretwister]

I have a 12/24 volt setup, has 4 wires at battery hookup and 3 prong plug on bow as well as battery 1 & 2 switch w/voltmeter and a run/charge switch.
My question is: Which wires do I use to go with 12volt only at the battery ???
I just bought this boat and previous owner used battery 2 and that doesnt seem to be right....12volt trolling motor runs slow and the voltmeter will show 12volt on both positions....I wanted to run a fishing light off the bow plug and it is dim as well.........Any help??

Thanks
Wire

 

[wiretwister]

Re: 3 prong trolling plug

After doing a lot of reading here.......I understand the wiring other than one battery hooked to battery labeled as #2.
I think my issue may lie on the wire size.....may not be factory wire(looks mighty small).
Wires for battery #1 are way bigger.
Is it ok to use all 4 wires for a 12 only setup ??? (i do have the 4 wires at batterys with the jumper at the "charge/run" switch)

Wire