quick trolling motor wiring question

[limited out]

Hi, I have a 70 thrust Minnekota tiller sytle trolling motor and my wires starting smoking and went haywire this morning while fishing.

Question on the wiring: there is a black and a black/red cord coming out of the trolling motor that are jimmy rigged to a three prong plug in for the boat. The black cord is wired to the black on the three prong, the black/red is wired to an orange wire on the three prong, and then there is a red wire coming out of the three prong just hanging loose. Can someone please tell me if i need to wire the red on the three prong also to the black/red wire for the trolling motor similar to the orange wire? Any help is greatly appreciated...

[delcecchi]

That is a 24 volt motor, right? Not a 12/24?

If it is 24 only then it only needs two wires.

[Whoaru99]

Typically the color code for that style of plug is:

Black = common ground/negative

Red = +12 volts

Orange = +24 volts

Assuming the boat is wired that way then the 24V motor should be connected to the black (to motor black) and orange (to motor black/red) wires and the red from the plug would be not connected.

Since the wires started smoking the very first thing I'd do is check there are fuses or circuit breakers of the correct size coming off the batteries. These are to protect the wires from burning, possibly taking the whole boat with them. The smoke is indicative of either no fuses/breakers or fuses/breakers too big for the size of wire.

[delcecchi]

Since the smoke was a sudden thing... It was, wasn't it? I would check any splices or connections. If they start going bad it would make stuff get hot.

[limited out]

Thanks for all the replies. Yes the smoke was a sudden thing but my wires leading to the 3 prong plug in the boat have been hot for some time. I think my issue is starting this summer i have been only running my 24 volt trolling motor off of one battery. I also believe the spices were rotten which could have led to it. Sounds like regardless if my warrior boat has teh 12/24 option, i need to run it off 2 batteries since my trolling motor only says 24 volt, correct?

[Whoaru99]

Far as I know running the 24V motor on just 12V shouldn't have caused smoke.

Sounds like it's time to call on a friend who has a multimeter and some interest in wiring.

[Jeremy airjer W]

Far as I know running the 24V motor on just 12V shouldn't have caused smoke.

Sounds like it's time to call on a friend who has a multimeter and some interest in wiring.

[delcecchi]

I am surprised a 24 volt motor will even run on 12 volts.

Depending on the type of wire, it can rot inside the insulation due to corrosion which would make it run hot also. Maybe it finally corroded down to about 1 strand...

[Whoaru99]

That is true. If there is a high resistance (relatively speaking) connection due to corrosion, bad splice/crimp, loose terminal, etc. that can cause localized heating enough to melt/burn the insulation.

A voltage drop test between one end of a conductor and the other, while under load, is a good way to see if there are bad connections (or excessive voltage drop). A theoretically perfect wire would have zero voltage drop and an open wire would show full voltage drop of the circuit's supply voltage.