if you check just one battery you will have 12v. if your jumper wire is hooked up to negative on one and positive on the other it's 24v. put your meter on plus and neg where the trolling motor wire's connect see how many volt you have
what you think i come on here with out trying to google it and researching it for weeks. this will be my first outboard always had a detroit diesel in my boats 3-71 - 4-71 SO KAREN if you don't have any helpful info to add just hit the ignore button
