12/24 trolling motor battery connection

I just purchased a 1989 Javelin 378 and it has the original OMC 12/24 foot control trolling motor w/ 3 speeds. In the back it has 2 red and 2 black cables for connection to the trolling motor. It only has 1 battery in now and I have the 2nd ready to go in but I would like to be sure how to connect the batteries. I was wondering if they connect in series or parallel, because when I was buying the boat we could get the trolling motor to come on with connecting only one set of cables and it would only work w/switch on 24 and the speed didn't change beyween the 3 settings. I was thinking they should connect red on + and black on - on each battery, but that won't produce 24 volts. thanks for any help this is my first boat and can't wait to hit the lake today.

Re: 12/24 trolling motor battery connection

Do a search on this thread -- I've provided a number of diagrams and descriptions on how to do this. If you have two red and two blacks, they simply hook up as you suspected -- red on +, black on - but make sure you have the red and black paired properly. The motor should have a 12/24 switch on it so that's how the 12V or 24V operation is achieved.