I decided to check my buddies 3 bank battery charger, on the 1st bank the red light stays on(saying bad connection) and is connected to the cranking battery which doesnt charge, the other two banks are green and connected to the trolling motor batteries. I hooked the bank 1 lead (cranking & bad) to one of the trolling batteries and the #2 lead(trolling & good) to the cranking battery. The trolling motor battery was red(bad bank) and the cranking battery was charging, so am I right assuming the 1st bank on the charger is bad?