OK….it was working and then you did **something** with the batteries and now it doesn’t work? That’s where I’d start looking, at that battery hookup. Plus to minus and all that, make sure there’s 24 volts there.
Does the trolling motor have a built in charge indicator? My MK has a button you can push to see how the battery is doing. I doubt it’s very accurate but it does show if you’re getting power up to the motor or not. Basically you have to start on one end of the circuit or the other and see how far the power gets.
Finally most “electrical” problems turn out to be mechanical problems: connectors, switches, fuse holders, busted wires. Look at those things carefully.
Rootski