outdated TM 12/24v setup?

[motodave]

Hello, Ive searched quite a while on here and I cant find any info on the current trolling motor setup I have. I have a 1999 motorguide 767 brute with the 12 or 24v option. Overhauling the battery box wires as the breakers and wires for the 2 TM batteries are toast. It works right now, but if I run on high w/24v settings it will pop the breaker. My original plan was to convert the setup to a 2 wire like the modern boats, but Im not sure if this is possible has anyone ever done it? My TM plug up front has 3 wires, but in back there are 4 wires hooked into breakers and the 2 TM batteries. I haven?t had time to pull the panel up front but Im assuming that?s where the extra wire is spliced in. They are 10 guage wires. I was planning on just splicing in new wiring at the back, and installing 2 motorguide 50amp breakers, would this be ok? Thanks for any advice!

 

[gm280]

If you swap over to a single 24 volt system at the battery box, you will loose the ability to go from 12 to 24 volt option. If you are solely only interested in a 24 volt setup, then you can series the two batteries together at the actual battery box and run only two wires forward to the trolling motor plug, in the front with one breaker of 50 amps. and forget the 12 volt ability. Depending on the length of the boat, you may need heavier wire then 10 gauge to satisfy the current draw. Don't splice bigger wires in at each end! Replace the existing wires with either 6, or even 4 gauge wires. And if for chance you still want a 12/24 volt system, series the batteries together at the battery box and run three new 6 or 4 gauge wires forward. One from battery one's negative terminal, the second wire from battery 2's positive terminal, and the third wire from the series wire between the two batteries as well. Then you can switch from 12 or 24 volts still. The fourth wire won't be necessary...

 

[Silvertip]

You cannot have both a 12 and 24 volt system with only two wires. One or the other but not both. For a combo 12/24 setup you need either a three or four wire setup. Some bow panels have a 12/24/Run/Charge switch. Some motors have the 12/24 selection on the motor. We need more info to help you. If the motor runs ok but pops the breaker periodically, check the wire size and then replace the breaker with the proper size. Chances are the breaker has tripped so many times it is no longer capable of handling the current it is rated for (meaning it has de-rated itself which is what breakers do when they operate too often).

 

[motodave]

gm20 you the man! Thank you so much! I would like to keep the 12/24v option. To make sure I understand, the series wire (going from + on batt 1 and - on batt 2) is where I run the 3rd wire from correct? Just splice into it or hook to + or neg terminal? And no breaker or fuse on the 3rd wire? This makes more sense to me, as the TM plug up front has 3 wires. Thank you again!

 

[motodave]

Silvertip thank you, I do have the batt charg switch on my panel up front, I'm going to take the panel off real quick and post, I was under the assumption that 2 wires leading to each battery and 2 breakers were neccessary to have 12 and 24v setup. Thanks again!

 

[gm280]

motordave, If you are going the three wire route to allow both 12/24 volt setup. Install the 50amp breaker at the negative wire of the first battery. That way if you use either 12 volts or 24 volts you are covered... Use good clean 6 or 4 gauge wires as well for good current capability... :thumb:

 

[motodave]

Ok got some pics hopefully will help, you can see the 4 main wires red, black, orange and yellow. The black and red are NOT hooked into the breakers, just the orange and yellow

 

[motodave]

Chit says photos too big, just have iPhone. Gm20 I think I know what you mean, just not understanding where the 3rd wire is hooked into?

 

[gm280]

The third wire goes to either the battery one's positive terminal. OR to battery 2's negative terminal. There should be a wire between those two places for the 12/24 volt system. Does that make sense?

 

[motodave]

Yes it does gm20, thank you much for explaining it more than once!

 

[gm280]

motordave, no problem. I can make the simplest issue seem complicated with words that I need to explain better so many time...

 

[Silvertip]

With a four wire system you have two wires from each battery going to the panel at the bow which amounts to two separate 12 volt circuits. A 12/24 selector switch makes the series or parallel connection for 12 or 24V selection. If you want to change to a three wire system there is more to this than just adding the series jumper at the batteries and adding the third (12V) wire as GM280 explained. Keep in mind the switching at the bow is involved and you need to reconfigure that. I would seriously consider keeping the four wire system as it is truly a 12 volt parallel and a 24 volt series system. The three wire system uses only one of the batteries for 12 volt operation.

 

[motodave]

Silvertip thank you very much for the response! I have decided to keep the 4 wire system after seeing the panel up front (all the switches and battery charge feature still works). All the wires up front look good and clean. Im just gonna get clean connections, 2 new 50amp breakers and run it, if I have issues I'll look at upgrading. Thanks again!