12v to 24v Trolling Motor fuse problem

Can anyone help me trouble shoot the following issue:
Removed Minn Kota 40lb 12v motor 2 wire plug
Replaced with Minn Kota 12 or 24 volt 65lb motor three wirw plug
Used existing wiring (4-2 red/2 black) and wired two batteries iin parrallel according to diagram (reviewed repeatedly and deemed correct)
Plug in new motor turn on 12v switch or 24v switch (didn't matter which)
35 amp fuse immediately blows.

Is the fuse to small for this application or is there another problem?

Re: 12v to 24v Trolling Motor fuse problem

Couple of issues you need to address.

You DO NOT wire a 12/24 system in parallel. 24 volts requires requires a series connection. There are many different wiring schemes used in various boats that were set up for 12/24 systems.

Here is the most popular setup if your motor has a THREE-WIRE hookup between the motor and the receptacle. Note the wiring very carefully. Note that the two batteries are wired in series so the red and black wires provide 24 volts. Note also that there is an orange wire connected to the first battery. That wire provides the 12 volt feed. The switch on your motor controls what voltage is selected. When operating on 12 volts only the left battery provides power. So for your wiring, you don't need one of the red wires. DO NOT remove it. Just disconnect it and tape the ends. If you sell the boat the new owner may need to use it and would appreciate it being left in tact.

If your boat has a separate switch panel that has a 12/24/Run/Charge switch then you will need all four wires. So make sure you let us know exactly what the entire troller system consists of.

Lastly, a 35 amp fuse is not big enough. That motor probably draws 42 amps but that would be at full speed. I would also suggest you eliminate the fuse in favor of a 50 amp circuit breaker.

Re: 12v to 24v Trolling Motor fuse problem

Thanks Silvertip. I always confuse the parralell/series wording.
I'm still a little confused by the diagram and one of your comments.
My diagram, from Minn Kota, shows the red wire taking the 12 v and the orange 24v. Why might this be, and does it matter?

You mentioned not needing the other red wire? Isn't that what is connected to the orange through the plug (harness)?

Re: 12v to 24v Trolling Motor fuse problem

I stand corrected -- it is one of the black wires you don't need. (Fingers going faster than the brain.) One of the red wires will be used where I show an orange wire. If you go back and read my previous post you will see where I described two different 12/24 volt systems. While your boat was wired for a bow panel that included a 12/24/RUN/CHARGE switch, yours does not have that feature (at least you have not answered my question about that). That system required separate wiring of each battery to the bow panel. Since your motor has a three wire connection, you only need three wires from the batteries. 1 for 24 volts, 1 for 12 volts, and one ground. Count them in my diagram. If Minnkota wants 24 volts on the orange wire, make the red wire in my diagram orange (or pretend it is). If they say 12 volts is on the red wire, then make the orange wire red. The fourth wire in this system is not needed.

Wiring need not be a mystery. Start at the positive post of the battery on the right. That post is the one that will deliver 24 volts to the receptacle. So if Minnkota wants that to be orange, pretend it is and use one of the red wires. Make sure the other end of that wire goes to the terminal on the receptacle that will feed the ORANGE wire on the trolling motor plug. OK - one down a couple more to go. Now prepare and run a jumper between the POSITIVE terminal on the battery on the LEFT, and connect it to the NEGATIVE terminal of the battery on the RIGHT. Now connect the remaining RED wire to the POSITIVE terminal of the battery on the LEFT and run it to the terminal on the receptacle that matches the RED wire on the trolling motor plug. Pick one of the black wires and connect it to the NEGATIVE terminal of the battery on the LEFT. Connect the other end to the terminal on the receptacle that matches the BLACK wire on the troller plug. Now use markers to identify each wire so if you disconnect them you know where they go. They will be +24 volts, +12 volts, Jumper, and Ground. Done! Go fishing!

Re: 12v to 24v Trolling Motor fuse problem

I read beneath a reply on another topic, "why is it that we don't always have time to do it right the first time, but we have time to do it again". In my efforts to do this properly I have started from scratch numerous times only to fail and fail again. Finally, I grabbed the package from my aftermarket plug to see if there was anything I was missing. Sure enough the three wire plug was constructed to operate either a 24v or 12v trolling motor not one that operates both ways. Furthermore, the shoddy directions on the cardboard tab explained that a jumper between batteries wasn't needed because a crossover was wired into it. This is obviously the major malfunction, and of course my failure to read the packaging! I slid the old 12v back into the mount and am ready to fish my entire vacation this week, the second battery will provide my with a much longer fishing day.
Thanks for your help.
I'll tackle the wiring another day.

Re: 12v to 24v Trolling Motor fuse problem

35amp fuse? Im pretty sure 50 or 60 amp is needed. Maybe though because your now 24volt it takes less amps