the trolling motor that came with the boat i just bought is a 1978 MotorGuide model 3400. The seller had taken out the 2 batteries, so i just picked up 2 new ones.

the problem is that instead of just hooking up the 2 batteries in series and connecting the red wire to positive of one and the black to negative of the other, there is a third wire that i dont know what to do with... it looks like another red wire with a black extender on the end. its part of the same bundle.

anyone have any idea what i should do with this extra wire?

thanks!

I'm not familiar with that trolling motor. Is it a 12 volt or 24 volt? If its a 12 volt motor one of the wires is unused. You will have to try each one at a time to find the one connected to the trolling motor.

sorry, its a 24v Brute

Is it a brute dura amp? I have one....if it is.

Is so...it's 24V ONLY....not a 12 or 24 switchable.

The 12/24 option is the reason you have three wires running to the front plug from the batteries. On red goes on the other positive battery pole...creating a 12 V connection....even with the batteries in series.

this thing says Brute F1, the diagram says "4 speed 12/24 volt" model 3400. the problem is the wiring diagram doesnt show the battery connections.

so you are saying i need to have one red wire connected to each positive pole, and the black wire connected to either batteries negative pole, or does it make a difference which one gets the black wire?

Is there a certain order i should connect these in to prevent sparks or death?

I hate messing with electrical junk.

thanks again everyone, this forum is unbelievably helpful!

Unplug the trolling motor at the bow ( if it has a plug there)
I am assuming there is a short jumper wire somewhere to hook the batteries in series. If so...


Then connect as follows :

Battery #1 .... + = red
( -)= one end of jumper wire


battery #2 ....
+ = red AND other end of jumper
(-) black to motor

Then turn on the trolling motor. If it turns real slow on the 24V setting....swap your red wires at the batteries.

Old Frog is correct you have a 12-24vt 3 system and the wires are switched in the T/M housing.

One Battery has a Red and Black wire for 12 volt and the other red wire is for 24 volts via the second battery and a jumper wire.
Bat (1) 12volt Leads .......... Bat (2) 24 Volt lead


Black & Red to T/M ~~~~ (-) XXX (+) ~~~ (-)XXX(+)~~~~ Red 24volts to T/M
.....................................^^^...................................
..................................Jumper Wire....................................
Bazz

I got to chime in here as I have a similar prob. I have three wires on mine as well, 2 red and one black. I am wanting to run it in the 12V mode (has a switch on the foot pedal).

I have one red to the + pole and the black to the - pole. However, this 50 lb thrust barely pulls my 14' aluminum in the 5th speed. Also, I have to have the switch in 24V mode for the trolling motor to work.

Should I remove the red wire I have attached now and screw the other red wire on the + pole? Would this make a pulling power difference?

Switch red wires, and switch to 12V.

http://texasfishingforum.com/forums/ubbt...ion#Post2346984

I had found that post in the other thread yesterday, great diagram, but it didnt address my 3rd wire. but it does bring up another concern. I have seen several diagrams that show a "breaker" between the wire and the battery. My setup doesnt appear to have one.
1. do i need one?
2. since i have 2 red wires, will i need 2 breakers? (one 24v and one 12v)?
3. where could i get them?

y'all are great! sorry im so ignorant.

Is this why I really didn't have enough power to pull my boat? Or will I still have the same power after switching wires and the switch to 12v?

Fry 210

We all had to learn either thru education or asking questions... you just need some electrical education.

Yes it's best to have a breaker for each Red (+) power wire. Just about any Marine Supply has Breakers and most Marine Dealers like TFF Sponsor Rock Wall Marine.

in a typical 12 - 24 volt system you have a series circuit for the 24 volt side... which means you have a jumper from the positive post on Battery (1) to the negative on Battery (2) the wires to the T/M Black (ground) on Battery (1) and Red (Positive) from Battery (2) Think of it as stacking Dry Cells together in flashlight.. you stack the positive end to the negative end on the next battery to add the voltage of the two. The jumper wire combines the voltage.

To get 12 vts you just run a seporate Red (positive) Wire from Battery (1) to the T/M. it attaches right on top of the jumper.

It's best to do away with the 12 volt part because it uses twice the amps from the number 1 battery and then when you switch to 24 Volts the batteries equalize drawing amps away from the number 2 battery until they both have the same charge.

Lets say your T/M draws 40 Amps at 12 Volts on High at 24 volts it will only draw 20 Amps. Also with 2 typical series 27 Deep Cycle batteries you have 130 Amp Hours each or 260 Amps combined and you're only using half the amp draw you would with the 12 volt system so you get good power All Day. 20 Amps drawn from a 260 Amp reserve goes a lot farther than 40 Amps goes into a 130 Amp reserve capacity.

If you ever loose your main engine.. you'll be glad you have extra amps in reserve!

Bazz

All the electrical education payed off, yesterday i got the batteries hooked up and got the prop spinning in both modes.

problem now is the TM wont turn left or right. The foot peddel will move it one direction, but not back. It appears there is some sort of cable that may be bad. Anybody know if the turn cable thing is something that could be replaced, or is it just time for a new TM?

Took the boat out for its first trip yesterday... didnt last long. after i got it out, i realized that the guy who sold it to me connected the main stearing cable backwards, turning right made the boat go left. fixed that last night when i got home, but it was disappointing to not be able to really try it out.

thanks everyone!

Yeah, it sounds like the cable is broken or is really loose. If it's loose, check for a screw to tighten the tension below where the cable is hooked into the foot pedestal.

If the cable is broken, you can get a new one & easily screw it into place (i've broken my cable before & that's how it acted - it's a pretty easy fix)