# Instructional thread on hooking up 24v TM



## Vertigo (Jun 3, 2012)

Wire from one battery positive to one battery negative. Wire from remaining positive to fuse or circuit breaker. Wire from fuse or circuit breaker to TM plug. Wire from remaining negative to TM plug. Use a good quality plug. Most failures/fires start at the plug. Use tinned marine lugs on all cable. 6 ga is adequate for a 24 volt system. Batteries must be strapped or clamped down or otherwise constrained. If you use an onboard charger, wire as per charger instructions. The TM battery system should be isolated from the rest of your electrical system.

Carry a set of jumper cables if you want to use your TM batteries as a back up for starting.


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## MaGuyver (Nov 6, 2012)

Thanks Vertigo. I had thought about the jumper cables but did not know if that would work. It seems the easiest way to go but did not know if I would blow something. The thought was to put a battery switch on the system (TM(1) - off - boat motor(2)). If I had problems I would turn off the main motor switch and turn the TM switch to bm2 and start the motor.


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## swampfox (May 9, 2007)

Sounds like you finally got something to work on. What did you score?


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## swaddict (Dec 19, 2009)




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## MaGuyver (Nov 6, 2012)

> Sounds like you finally got something to work on. What did you score?


I will let you know next week.


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## MaGuyver (Nov 6, 2012)

>


Thank you


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## swampfox (May 9, 2007)

Nice we need to archive that.


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## Vertigo (Jun 3, 2012)

In the diagram above, it appears that with the battery switch in the #2 position, if the trolling motor is run, 24 volts will be applied to the accessories and motor.  This might not be such a good idea.

In any case, it's best to isolate the TM system from your electronics.  The signal from the TM can screw up a lot of electronics, just by being on the same ground.


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## MaGuyver (Nov 6, 2012)

Thanks Vertigo. I have seen this diagram done a couple of different ways. That is interesting about the ground.
If I just did the jumper cable idea, how are the cables connected when jumping a boat battery/motor?


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## swampfox (May 9, 2007)

My last boat that had24v was just simply wired off the batteries to the TM plug. Had it like that for six years without issue. My current HB was set up for 24v. And it was the same except a breaker was added between the TM and batteries. This to me is much simpler and keeps all the wiring up front. Kinda off subject but since you asked about jumping the starter battery. Can these new EFI engines still be rope started with a dead battery? Or do they need that voltage on reserve from the battery?Never really crossed my mind till now.


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## Vertigo (Jun 3, 2012)

> Thanks Vertigo. I have seen this diagram done a couple of different ways. That is interesting about the ground.
> If I just did the jumper cable idea, how are the cables connected when jumping a boat battery/motor?


Just jump in parallel from one TM battery to the cranking battery.


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