Negative Battry Wire Melting

[onewei364]

any idea why the Negative battery cable would start to melt? Just had my boat rewired for a battry bank and for some reason the motor battery starts to get really hot and melt the wire. The motor will start, but want to find out problem before it gets worse.

 

[dchris]

Re: Negative Battry Wire Melting

You have a big time short if it;s melting your cable. We will need better details to help much. The only clue you gave was your battery bank rewire. Thats probably the first place to look. If you're melting cables and not blowing fuses, you should keep the battery disconnected until you can figure this out.

 

[Dunaruna]

Re: Negative Battry Wire Melting

You have a big time short if it;s melting your cable. We will need better details to help much. The only clue you gave was your battery bank rewire. Thats probably the first place to look. If you're melting cables and not blowing fuses, you should keep the battery disconnected until you can figure this out.

A big fat DITTO!

 

[TBarCYa]

Re: Negative Battry Wire Melting

What gauge wire is it and how long is it? Was it premade cable or did you attach the ends yourself?

 

[PondTunes]

Re: Negative Battry Wire Melting

Make sure the switch for your battery bank is only connected to the positive wires... The negative wires for your batteries should be hooked together not through the switch. Likewise double check all your connections as a loose connection will cause wires to overheat as well.

 

[jtexas]

Re: Negative Battry Wire Melting

First, make sure your fire extinguisher(s) are charged up.

Second, disconnect the battery cables.

Next, get a new negative battery cable - that one has damaged the insulation if not the cable.

Then, describe your "battery bank", how many cables are involved, and what each one is attached to. Draw a picture if you need to. Then we'll be happy to talk you through it.

 

[Tom 47]

Re: Negative Battry Wire Melting

Check the battery I had a similar thing happen where the negitive battery post it melted. The cells in the battery shorted out causing the short that melted the battery post. Check everything and disconnect the battery cables.

 

[bruceb58]

Re: Negative Battry Wire Melting

Does it only get hot while you are cranking? If so, could be a resistive connection at one of the cable ends.

 

[Have Fun Today]

Re: Negative Battry Wire Melting

After you disconnect your batteries (all of them), I'd suggest taking a close look around your and battery engine compartment. Look at wires to see if there is any more electrical damage from shorting...look for burned and black insulation, stiff wires, etc (stranded wires that melt become stiff after cooling). You might find the obvious short. If not, you may need to get an ohmmeter and start by checking the impedance at the battery connections, then disconnect electrical items and turn off switches to isolate the short.

I had some engine work done by a boat shop (now on my black list)...they set a battery on top of a red battery cable and broke the insulation down to the wire.

 

[onewei364]

Re: Negative Battry Wire Melting

Thanks for all the support, I will try to go into more detail as possible.

1st as you can tell I know nothing about motors, so bare with me in detail

I had the boat rewired from front to rear by a licensed boat electrician because the previous owner had all wires screwed up and looked like a birds nest. The electrical person installed a 3 bank 30 amp Guest charger 2 batteries for trolling 1 for motor. I have taken the boat out once since all wiring was complete no problems except some gauge problems. So after trying to go out a 2nd time attempted to start and would not turn over.

As for the guage of wire not sure it looks to be original and from doing some research it looks like the motor is a Honda 4 stroke 90hp built around 1996-1998. It is about 4-5 feet long. The end were made after the rewiring.

Check for loose connections found none that I can see. Extinguishers charged and in boat standing by.....

Does get hot while attempting to crank, also will not start.

Hopefully this is better info to try to figure out problem I will get a new negative cable today. Is it hard to install if you have little knowledge? I have done it for a vehicle replacing battery cables, but never a boat.

Again thank all hope to hear back

 

[Have Fun Today]

Re: Negative Battry Wire Melting

On your original post, you said the motor would start...now it won't? I don't think you should turn it on with a short. If you don't feel comfortable disconnecting the batteries, remove the key and stay away from them.

The problem is not fixed and could be causing additional damage you can't see (yet). If the negative battery cable is hot enough to melt, then somewhere there is an electrical connection from the positive post on the battery that is feeding the short. This means there is an equal amount of current coming from the battery, possibly doing the same damage to an unseen wire. Replacing the negative battey cable won't change anything if you don't locate the short.

I have 2 gage wires for my battery connections (I think) and they're enough to handle the load to crank my 5.7LX without getting hot.

Any chance of having the electrical technician who did the work take a look at it? Sounds like he may have overlooked something. If he's licensed, he should cover the damage caused by anything he connected improperly.

 

[onewei364]

Re: Negative Battry Wire Melting

I disconnected the battery, I will have him look at it again and see what problem is. As for starting I tried and it won't and since I noticed the wire melting I gave up like I know I sshould do.

Thanks

 

[wire2]

Re: Negative Battry Wire Melting

A poor connection between the cable clamp and negative post, plus 5 seconds of cranking can & will melt a cable end or lead battery post.

You're dealing with a low voltage, high current through a resistance situation similar to welding, and a lot of heat is generated in a small area.

A short would usually continue to cause heat & smoke after the starter is released. A short would also draw equal current through both neg and pos battery posts. In this case the pos is ok, (as I understand)

I believe you'll have no more problem after you replace the smoked cable end with a new one and tighten securely.

 

[Have Fun Today]

Re: Negative Battry Wire Melting

Is the entire negative cable hot and melting (burned insulation, stiff wire) or is it limited to just the battery cable clamp and battery post? One would be a short, the other possibly just a poor connection to the battery as the previous post points out.

 

[onewei364]

Re: Negative Battry Wire Melting

about 2 inches from post, so I cut and reconnected and seems to work, but other issue before I try starting again.

Now tilt not working, posted a forum help on the Honda Motor section. If you can help great