Motorguide 24v 80lb thrust, wire to battery SUPER hot

[vcaptain]

I was out on the lake today, and my trilling motor shut off. I thought maybe it was a loose connection, so I grabbed the Pos, nut on the battery and burned my hand. The insulation was melted off. My said he thinks there is some resistance in the wiring causing it to over heat. Any thoughts? Should I replace the wiring with a heavier duty gauge? Any advice is appreciated, thanks guys.

 

[Silvertip]

What is the current wire gauge and are there any other corroded or loose connections?

 

[gm280]

Sure sound like too small a gauge wire to me. I would replace both the positive and negative wires from the battery to the trolling motor. But with a wire gauge that will handle the current your trolling motor requires for that length of run and current. This is a prime example of how a fire can start on a boat. JMHO

 

[sam am I]

If the TM has ran normally for some time now beings ran as you just did with never any problems, nothing has just been changed/modified such as new wiring just added etc and it never had burning/hot wires before and has ran normally not shutting down like this in all of the past and it just shut down today? POOF!! Out of the blue!! Something has had a definitive change just recently IMO

I think then, your current/existing wiring as it is/was, is probably fine.

This new problem could be shutting down the motor for a few reasons here I figure,

1) Under-voltage/low supply voltage sensed at the motor, caused by

a) Low battery​

b) Bad connection/s.......Check for corroded connection (as stated above) at the site of the hot spot/s, this/these spot/s are higher resistance areas and are dropping higher than normal voltage due to higher then normal resistance, V = I*R and heating up, P = I*V or otherwise put, Watts = Current x Voltage and Watts are heat.​

2) Over current sensed by the motor, caused by

a) Bad bearings, rusted up locking armature, fishing line wrapped, weeds wrapped etc, etc all preventing the motor from spinning freely.​

b) Shorted winding's/commutator in the armature (assumes brushed motor).​

3) An in-line breaker opening, caused by

a) See 2a/2b​

Since you had extra high heat/melting wires, I'd probably check 1b, if connections all look good/tight/clean, then an over/abnormal current situation is most likely concurring and then I'd move onto 2a and/or 2b.

 

[vcaptain]

What is the current wire gauge and are there any other corroded or loose connections?

I'm not 100% but it looks like 10ga wire. What gauge should I use for a 24v? 8?

 

[vcaptain]

If the TM has ran normally for some time now beings ran as you just did with never any problems, nothing has just been changed/modified such as new wiring just added etc and it never had burning/hot wires before and has ran normally not shutting down like this in all of the past and it just shut down today? POOF!! Out of the blue!! Something has had a definitive change just recently IMO

I think then, your current/existing wiring as it is/was, is probably fine.

This new problem could be shutting down the motor for a few reasons here I figure,

1) Under-voltage/low supply voltage sensed at the motor, caused by

a) Low battery​

b) Bad connection/s.......Check for corroded connection (as stated above) at the site of the hot spot/s, this/these spot/s are higher resistance areas and are dropping higher than normal voltage due to higher then normal resistance, V = I*R and heating up, P = I*V or otherwise put, Watts = Current x Voltage and Watts are heat.​

2) Over current sensed by the motor, caused by

a) Bad bearings, rusted up locking armature, fishing line wrapped, weeds wrapped etc, etc all preventing the motor from spinning freely.​

b) Shorted winding's/commutator in the armature (assumes brushed motor).​

3) An in-line breaker opening, caused by

a) See 2a/2b​

Since you had extra high heat/melting wires, I'd probably check 1b, if connections all look good/tight/clean, then an over/abnormal current situation is most likely concurring and then I'd move onto 2a and/or 2b.

The motor is basically brand new (one year old, used a dozen times) , I typically have not run it for as long as I did yesterday, which may explain why the fuse had not popped before. I think my best option is to run a new wire, what is the going suggestion for gauge? I think there is 10 there now, so maybe 8 will due it?

 

[vcaptain]

Thanks for all the advice, I ordered 20ft of 6ga marine wire, hopefully that'll solve my issue.

 

[gm280]

Thanks for all the advice, I ordered 20ft of 6ga marine wire, hopefully that'll solve my issue.

I think you did the right thing ordering new wire. I bet that fixes all your problems as well. :thumb:

 

[sam am I]

The motor is basically brand new (one year old, used a dozen times) , I typically have not run it for as long as I did yesterday,

Ahhhhh, okay. Yeah 6 AWG marine grade should work well, 10 is a bit on the light side.

 

[vcaptain]

That's gotta be it, it's a 200oyr boat with a 2016 TM 80lb, who knows what he had, Thanks again for the input, it's always great to talk to other boaters!