12vto 24v trolling motor plug

[cerveza fria]

I am hooking up a new 24v 80lbs thrust riptide. The dealer gave me a three prong plug. Only two wires come out of the tm, 1red, and 1red/black. THe plug has 1 red, 1 black and 1 orange. I am going to hook the reds together and the black to the red/black on the trolling motor. This will leave the orange wire unterminated. I plan and hooking the red on the recepticle to the red coming from the batteries, and the same for the black. Once again this leaves the orange wire. After i wire the batteries in series, will i Have 24volts at the trolling motor? If so what is the orange wire for?