Trolling Motor Switch

[propster]

Thinking about putting the 24v trolling motor from my "new" boat ('95) on my "old" boat ('93), which is only set up for 12v (1 battery). Is that doable? Do I simply need to cut off the plug and attach the correct one for the different recepticle on the other boat, or might the wires not be compatible? Will the motor run on just one battery? Thanks.

[marine_man]

You will need to wire the trolling motor to work with the plug on the other boat. Then, you'll need to add a new battery, and connect the negative cable to your trolling motor to the negative post of one battery, and the positive cable to your trolling motor to the positive post of the other battery. Then, make a jumper of 8 or 10 gauge wire and run that between the open posts of the two batteries - negative to positive.

No, the motor won't run off just one battery - that'd only be 12 volts.

marine_man

[propster]

Thamks MM. When you say connect the negative and positive cable of the trolling motor to the the different batteries, do you mean the negative and positive side of the recepticle on the boat?

[marine_man]

No... that would happen at the batteries.

Here's a schematic that might help:

marine_man

[propster]

Hope you can have some patience with me here - are you saying wire the trolling motor wires directly to the batteries? If so, why is the plug still needed - and how would I still plug my charger into the boat receptacle in order to charge the batteries?

[boatfixer]

You would still use a plug. The wires on the back of the plug (boat end) would connect to the batteries.

[boatfixer]

If MM has anymore diagrams, I'm sure he will put them up.

[marine_man]

Switching to a 24 volt trolling motor and wiring it in the manner shown above means you will not be able to charge the batteries through the plug, like you perhaps had been with the 12V system.

Let's go back to the beginning here... what kind of trolling motor plug do you have? One with two, three or four pins in the connector or receptacle?

How many sets of wires do you have running to your battery.

You will still wire the trolling motor to the plug, and the receptacle to the batteries... no change there.

marine_man

[propster]

I've got it now. When I asked for clarification after you said attach the cables from the motor to the battery, and I asked do you mean attach the boat recepticle to the batteries, and you said no, that threw me for a second. Boatfixer says the recepticle, and I think you also confirmed it's the recepticle in your last post, right? Last question, I hope, do you recommend changing the plug on the motor to fit the boat (3 pin) or the female plug on the boat to fit the motor (which I think is 4 pin but it's stored and I do not remember)? I'm thinking I should change the female plug in the boat?

[marine_man]

Let's back up...

What kind of boat do you have? And, how many pair of wires do you have running to your battery compartment? Does / did it have two battery trays?

If so, the wiring is going to be completely different.

With respect to the plug, I would rewire the trolling motor plug side... it's quite a bit easier than dealing with the boat end of things.

marine_man

[propster]

The boat is a '93 Lund Angler II. The way it currently is set up: From the plug-in at the bow (recepticle) I am pretty sure there are 2 wires going to the battery - one black one red. Might be a ground also but I'm not sure until I look at it (at my buddy's) And only one battery is hooked up to these wires. I would like to plug a 24v motor into this same recepticle. What I took away from your descriptions above - I wire the recepticle as you describe - red to pos. on one batt, black to neg. on other battery, and make a jumper between the two batteries. Then change the male plug on the motor to fit the female plug on the boat. Have I got it and is it doable? But I can't charge the batteries through the plug with a regualr charger, because they are now a 24v system? Can I hook up the charger directly to each battery without disconnecting them from each other or from the boat? If not then this whole deal may not be worth doing. Thanks MM.

[marine_man]

Yes, you've got it, and it's doable.

No, you can't charge through the trolling motor plug in this configuration. You have 24 volts at the female trolling motor plug, and plugging in a 12V charger won't work.

You can charge by just putting the alligator clips from the charger on one battery (neg to neg of one battery and pos to pos of the same battery).

Now, if charging through your trolling motor plug is a big deal to you, you could re-wire your boat for two pairs of wires running to the female plug on your boat.

Another option would be to buy a on-board charger and leave the cables connected all the time and plug it in when you're not fishing.

marine_man

[propster]

Perfect, and thanks for your help. Nope, I don't need to charge it through the plug because I would use it infrequently as a backup and for smaller lakes. Alligator clips on the battery itself are just fine 'cause I can get at 'em easily, but do I have to disconnect the other battery when I am charging one at a time?

[propster]

Last thought MM. When I re-wire a new male plug on the tm, taking it from I think 4 pin to 3 pin to match the female side - are there any extra wires on the tm cable I need to be concerned about, and if so where do they go on the new 3 pin male plug?

[marine_man]

No, you won't need to disconnect the other battery.

You'll have to take a look at trolling motor and see what it has for wires.

marine_man

[propster]

I appreciate all your help.

[marine_man]

No Problem!

Good luck on your project!

marine_man