Re: Going to 24v from 12v TM
You can easily do this but you will need a three terminal receptacle up front and both motors would then need to have three terminal plugs even though only two will be used. Leave the 24 volt system as it is at the battery end. The new three terminal receptacle will have red, orange and black wires on it. Connect the 24 volt system to the red (positive) and black (negative) terminals. On the 24 volt troller, add the new three terminal plug using the 24 volt (red and black) terminals.
Now for the 12 volt system. Run another wire via a circuit breaker, from the positive terminal on the FIRST battery (the battery with the black ground wire attached) to the terminal that has the ORANGE wire. If you now use a voltmeter to check the receptacle, Red to Black = 24 volts. Orange to black = 12 volts. Now the install the new three terminal plug on the 12 volt motor. WARNING: Make sure you connect the positive wire on this motor to the ORANGE wire. Black connects to black. You can now use either motor. No switches needed. Both batteries will be in series for 24 volt operation and your 12 volt motor will run from the first battery in the system.