I'm kinda surprised it works at all on 12v. Is this Larry G.'s old Lund? I'd expect better from his dealer of choice, but a lot of the rigging is done by minimum wage types. Kim's Smokercraft had the TM harness disconnected from the battery harness, for instance. It wouldn't have taken much to check for power, and a .5 second blip on the TM won't hurt anything, either.

Not sure what wiring scheme you have, but my boat had orange and red wires, two each, one of each from bow to each battery. I wish they'd used red & black, but it doesn't matter, of course. What I did was hook both orange wires to the negative pole on one battery, and both red wires to the positive pole on the other battery....all while both were unhooked from the bow panel. Both orange wires connect to the negative side at the bow panel, both red wires connect to the positive side at the bow panel. As I recall, the +/- marks are actually on the plug, not the receptical. Then, you need a jumper wire to connect the positive pole of the first battery to the negative pole of the second battery. I got mine at the auto parts store...B&B, probably. This puts the batteries in series, so 24v. The reason you double up on the wires is because they'll carry twice the current and reduce the electrical resistance, so don't get hot and cause yet more resistance. Or fires.

I'd suggest circuit breakers instead of fuses. Circuit breakers don't last forever, either. If you are on TM because your big motor is TU, and you blow the fuses, you can be in deep trouble at some lakes, in some situations.

Assuming you have an onboard battery charger designed for at least two batteries, just hook the pairs of leads to one battery per pair. They are designed to do that, and it works fine, highly recommended. Give me a jingle if you need more help or info.

Rock on. Confirmed with you guys and a couple of other experts, as well.

Thanks!
Stu

Hook the charger to the batteries and you will be fine.

Shouldnt have to Stu as they will charge as the dis-charge....my un-educated quess.

Thanks to Jim Rumann, who came over today and helped me to install a new 3-blade locking 24-volt plug. Now the trolling motor works at 24-volts!

New question: Now that I have the batteries wired in sequence to make 24-volts, do I have to do anything special with my 3-bank charger? Does the jumper wire between the two trolling motor batteries have to be disconnected before I charge the batteries?

Thanks,
Stu

I took the advice listed here. Checked everything and it looks like the reason it keeps smokin is that the plug is fried. (Not sure if it fried initially or if we helped it along when we tried to "fix" it. I'm taking it in to Auburn S&M on the 30th to get everything back up to code and running right.

Thanks,
Stu

Stu, check the foot pedal, sometimes the 12/24v selector is on the side of the pedal.

Faz

Ahhhhhh. Maybe the boat does have the switch. I assumed it would be on/in the motor, but I haven't gotten that far yet in my "research." I'll check it out.

Thanks,
Stu

Stu,
  One more thing.  Make sure that your boat doesn't have a switch that creates 12/24 volt.  If that were in the wrong position when you hooked it up, not sure what would happen.  Maybe smoke!

Stu,
  You need to disregard the orange wire.  Mine isn't hooked up either.  To create 24 volts, you connect the red lead to a positive terminal of one battery, the negative of that battery goes to the positive of battery 2.  The negative of battery 2 goes to the black wire of your trolling motor and WAALAH, 24 volt wired correctly.  BTW, I'd pull the fuse until you get all this worked out.  This scenario is how guys end up with battery acid all over them.  Call me with questions.  I'll help any way I can.  Good luck

Dang Professor Smitty...I'm impressed.  Thanks for the class...Sorry funding cut short this semester due to lack of Govt support.  IOU

CP

No the "T" motor would not run too fast, especially if it is an infinite speed motor as opposed to 4 or 5 fixed speeds on the dial.  There is a widely held misconception that 2 12 volt batts wired parallel to produce 12 volts, will last longer than 2 wired in series to produce 24 volts. 
The fact is the reserve is measured in amps.  2 12 volt batteries wired to produce 12 volts will draw down the reserve amperage hours quicker, than the 24 volt system that uses less amps at 24 volts to produce the same amount of thrust.  The less amperage used, the longer the batteries will last under a given load until they are fully discharged.  The same rule holds true for a 36 volt system vs a 24. 

All of these facts hold up provided the batteries being used are equal to each other at the start.  That is the same battery type with the same relative age and usage,  and charged to the same level.

So ends today's lesson in boat battery care 101.  Hold your appaulse, but pass the collection plate.

Yeah, they had a bunch of spots all over them, but I deleted all that clutter, so they are OK now.

Stu

Larry probably didn't have a choice with the 12V, his expert installation staff hooked it up that way most likely.  I think they messed up his fish finders too.  I think I heard people whispering about that before.

I can't figure out why Larry set it up at 12 volts on that boat. Would the motor run faster at 24 - too fast?

Stu