Trolling Motor Wiring

BloodyBill

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Feb 25, 2013
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I have a Minn Kota trolling motor probably from the 1960's. It has 4 wires coming from the motor, there is a pot/rheostat betweeen the motor and battery. I believe it is a variable speed, but it's not working. I would like to bypass the pot, but don't know which wires to tie to the neg batt terminal and which to tie to the pos.
 
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2,906
Re: Trolling Motor Wiring

not sure on that model but i thought the pot was a switch with 4 positions (3 plus the off position). last one i played with was black to negative then any one of the 3 to positive (each wire will give a diffrent speed). only connect one wire at a time and cap the other 2 so they dont short out.
 

BloodyBill

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Feb 25, 2013
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Re: Trolling Motor Wiring

I ran into a snag, I couldnt wire it like you suggested. I have red, black, green and orange wires coming out of the motor. The person who gave me the motor permanently wired/soldered the red wire to the pos batt cable. I hooked black to the neg batt cable and tried orange and green as well, but the motor didn't spin. Also, the potentiometer has a 1,2,3, L1 and L2 for each of the terminals.
 

Silvertip

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Sep 22, 2003
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Re: Trolling Motor Wiring

Pictures sure would help. And just for clarification, if this device operates like the volume control on a stereo system, it is a potentiometer. If it has distinct clicks or detents, it is a switch. You also need to describe the device (again a picture would help) since you tell us it has 1,2,3 and L1 and L2 for each of the terminals. So does it have three terminals, six terminals or what? Draw a diagram of the wiring and post it. Remember -- we can't see your boat and need to rely on a description thus far which has not been very clear.
 

BloodyBill

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Feb 25, 2013
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Re: Trolling Motor Wiring

Here are the pics. The switch has distinct clicks at 3,6,9 and 12, but like i said it doesnt change speed. I removed the wiring before documenting which wire was connected where because my plan was to wire the motor straight to the batt. But it is starting to look like I need a new switch.Minn Kota 2.jpgMinn Kota 3.jpg
 
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Re: Trolling Motor Wiring

i have to ask......did this motor run when you first got it?
The next question is do you realy want to fix something that old when theres so many newer ones that you can buy used on craigslist cheaper than the cost of a new switch (if you are not in the usa then the cost may be diffrent)

on the old motor can you remove the cover at the rear to get to the brushes (looks like screws but may be rivets). A picture of the brush and wire set up will ans how the motor changes speeds and how it should be wired.
 

BloodyBill

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Feb 25, 2013
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Re: Trolling Motor Wiring

Yes it runs. The wiring to the switch was about to break, so I want to bypass the switch if possible. I believe you are right and it is screws. I will break it open and send some pics.
 

BloodyBill

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Feb 25, 2013
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Re: Trolling Motor Wiring

HPIM1706.jpgHPIM1707.jpgHPIM1708.jpgHPIM1709.jpg

Not much good taking off the cover. This is all you can see. The only way to see internal wiring would be to dismantle from the shaft end, and the bolts would probably be ruined they are so rusty. I would like to wire straight to the batt if anyone knows how to.
 

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Tracker john

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Mar 27, 2013
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Re: Trolling Motor Wiring

I owned one of these years ago. It is ok for a small boat. The switch in question should be a multi position switch not a continuous one. Originally there should have been a tiller and the switch nob was at the end.
 

gm280

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Jun 26, 2011
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Re: Trolling Motor Wiring

View attachment 183995View attachment 183996View attachment 183997View attachment 183998

Not much good taking off the cover. This is all you can see. The only way to see internal wiring would be to dismantle from the shaft end, and the bolts would probably be ruined they are so rusty. I would like to wire straight to the batt if anyone knows how to.

OMG WOW, I see so many things that need attention that for someone that does not understand about electricity/electronic and such things, it would be near impossible to talk you through that repair/fix/ rebuild issue with what I’ve seen. Not trying to be mean or rude or anything else, but that motor is in need of some major overhaul work. The armature could use a major going over for starters and corrosion is everywhere, I bet even in the windings... You’re positive you can’t locate a better trolling motor for your boat? And before I do forget it, don’t ever wire anything directly to any battery. Put a circuit breaker or fused link in between for starters. And a switch wouldn’t be a bad idea either. Reason for that is because if something started heating up the circuit breaker and/or fuse would blow stopping current flow and the possibility of burning down your boat... again JMHO! I’m sure I could fix your problem if I were there, but I’ll let more experienced folks on here assist...they have better capabilities to talk folks through such dealings! :facepalm:
 

Silvertip

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Sep 22, 2003
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28,758
Re: Trolling Motor Wiring

There are four wires one the motor that I can see. As such there are several options. One such option would be that one wire is +12 volts direct to the motor for high speed. One of the other wires is the ground lead and the remaining two are speeds 2 and three with 2 and 3 be3ing slower than "direct". Another option is that the case of the motor is the ground connection which would mean there are four speeds (Direct, and 2, 3, 4) with 2, 3, and 4 being slower than direct. All of this said, those old motors had speed coils in them which were wire wound resistors that were connected in various combinations to control speed. Those motors consumed the same amount of current regardless of speed because the coils wasted energy in the form of heat. You don't need to open up the switch to check it. An ohm meter and a few minutes time would prove it is either bad or good. Moving to the next option would be that this motor is actually wound with several windings to provide the various speeds. If there are no speed coils, that's what you have.

Here is a diagram that illustrates how a multi-speed motor achieves the speeds using speed coils. Although I show separate coils for each speed, they may be connected in series and parallel combinations via the switch so only two coils would be needed. The diagram is for concept only -- and not an attempt to illustrate your motor exactly.

MKPDSpeedResistor.jpg
 
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