Cables get hot

[crookedmullet]

I've got a Motorguide 36lbs. thrust 12volt trolling motor, and when I use it, the cables get pretty hot. It gets so hot that it melts the insulation on the ring terminals of the cable. It's the original cables and I haven't extended them, I've just shortened them a little to put new ring terminals on them. It has 5 speeds in forward and 2 in reverse and they both work fine, it doesn't seem to interfere with the problem. I was just wondering what I can do to fix it before it does become a problem?

 

[Andrew Leigh]

Re: Cables get hot

I am no expert on trolling motors but consider theses points.<br /><br />Has it always done this? Or is this a recent development?<br /><br />Cables getting too hot are the result of too much current being passed through them OR the cables are underated for the application.<br /><br />As you have said the cables are original therefore we can rule out the fact that they are underated. Having said which it is not inconceivable that you have a poor (high resistance) joint causing heating.<br /><br />If this is a recent development then your motor is drawing more current than it was designed for due to additional load like perhaps a bearing busy seizing up.<br /><br />Is the motor thrust correct for the size of your boat?<br /><br />Cheers<br />Andrew

 

[dingbat]

Re: Cables get hot

I've just shortened them a little to put new ring terminals on them.

Chances are your new rings are not the proper size or you didn't make a good solder connection. I'd suggest you cut off the ring and try again.

 

[jlinder]

Re: Cables get hot

Hot = dangerous<br /><br />Getting hot means that you have a problem. You didn/t explain, but I guess that it is hot only at the ends, which would be common.<br /><br />If so, look at the crimp connections and the terminals. Is the crimp tight? Try pulling it off. Is the wire corroded at the end? Look for the green meanies. Are the terminals corroded? Try emery cloth to sand and clean the connections.<br /><br />Cables getting hot also means you are losing a lot of power in the cables. This translates to a much shorter battery life.<br /><br />Let us know what you find

 

[crookedmullet]

Re: Cables get hot

Well, the crimps are tight for sure. I use the motor on a canoe so the motor is not getting strained from excessive weight. And even after using the motor all day, my battery is still more than 3/4 charged. Having a 12volt trolling motor do I need to have a 50amp fuse on my red cable? I've never used one, is this maybe causing my problem?

 

[SlowlySinking]

Re: Cables get hot

If the hot spot is only at the crimps and not the length of the cable then you have high resistance crimps. You can check your crimps by putting a volt meter on a low volt DC range and connect across the crimp, put one lead on the ring and the other on the wire so you are measuring across the actual mechanical crimp, if your volt meter shows a reading when you activate the motor you have a bad (high resistance) crimp. The higher the reading the worse the connection. If this tests okay then I would think your cable is too small and you are getting a voltage drop. You can check this using the same method noted above. Good luck, ken

 

[MrBigStuff]

Re: Cables get hot

I've got the same motor on my canoe.<br /><br />I extended the wires significantly so the battery can sit in the center of the canoe. I put a plug and socket disconnect in the line using an industrial grade, 220VAC connector set I had laying around. The original motor cables go into the male connector.<br /><br />I used something like 10ga wire for the extension. I twisted the wires using my hand drill to make a nice pair to route down the inside rim of the canoe.<br /><br />The battery side connections are simple clips like they use on a battery trickle charger. This is perhaps the worst part of the connections since very little of the clamps are in contact with the battery terminals.<br /><br />None the system components ever show any signs of heating above ambient temps even at full current draw of the motor for extended periods.<br /><br />Like the others said, you must have bad crimps- really bad to make it heat up like that.

 

[jlinder]

Re: Cables get hot

SlowlySinking has the right idea. Check the voltage at various spots.<br /><br />You can set your voltmeter at 12 volts and connect the neg. to the battery terminal. You can use any old wire to extend the test lead since there is no appreciable current flowing in the meter.<br /><br />Then take the pos lead of the voltmeter and touch it as close to the battery as possible. Turn the motor on. Do you see 12 volts or something signicantly lower? <br /><br />If 12 volts move the meter pos lead to the next spot, like the crimp connector that connects to the battery. At some point you will see a big voltage drop and that's where your problem is.<br />Move the voltmeter pos. lead closer to the battery

 

[crookedmullet]

Re: Cables get hot

I will check the voltage tomorrow and get back to guys. Do I need to have a fuse between my motor and battery?

 

[CN Spots]

Re: Cables get hot

Heck yeah!

 

[jlinder]

Re: Cables get hot

Forget the fuse. They just spoil your chances of getting to see lots of fireworks, smoke and flames

 

[crookedmullet]

Re: Cables get hot

Sorry I haven't replied sooner, I've been so busy, I just had a electrician friend of mine look at the motor. He found a loose connection. It was actually the post that was loose, which was causing the crimps to melt. He actually got a day of fishing in with the motor and he didn't experience any problems. Thanks for all the help. I decided to attach a 50 amp fuse to the cable to prevent any accidents.