What would cause Negetive battery side post to melt

DJM1972

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#1
Please fill out the following to ask a question.

MAKE:Chevy
MODEL:Cavalier
YEAR
:2001
MILES:not sure
ENGINE
:not sure
DESCRIBE ISSUE....
Subject: What would cause Negetive battery side post to melt on a:

2001 Chevy Cavalier



I've done a little searching on the www

And seems like there could be quite a few possabilities.



Positive side



  1. If there is a bare positive wire touching or grounding out. You would think for sure that it would have a melting eftect. This is where I want to go to 1st.

  2. Negetive side


    1. Bare negetive wire touching engine & or chasis. (Normally a ground but since its possibly a bare wire this would be a battery drain.) But this shouldn't cause it to melt.

    2. That negetive wire didn't look all that good. There is corosion at the chasis ground and a but conector between the battery and starter or solenoid. Which could be causing to much resistance somewhere somehow. (Replace)

    3. We can throw my battery in and make sure it does the same thing. Make sure it's not the battery.

    4. Its possible it could be a faulty starter or Alt. We'll need to figure out how to test these also. But how likely is it that this is the possability.






      Misc.
      1. Hood touching. But it was melting with the hood up.


      These are some of the possibilities but I'm sure I haven't thought of all them. If any one else has some idea's that would be great.
 

nickb2

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#2
I will try to respond with the simplest answer I can find, and if I make a mistake, one of my colleagues/friends here will correct.

Electron flow will follow the path of least resistance.

Remove any related wiring from that wire THAT IS MELTING. There is a cause to this.

It could be a short or ground issue. Todays batteries throw quite alot of CCA's. (cold cranking amps)

If that "wire" is melting, what is it connected to?? Starter? If the positive side is melting, put your bets on a bad ground. Not unheard of on these GM models.
 

nickb2

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#3
On most of these models, the ground bolt is located on the bellhousing of the transmission. Unless it was modified. Which may account for your trouble.

If the electron flow cannot return to ground of this circuit, any power wire, whatever gauge size will melt and potentially cause a fire. Especially since these engine like to leak oil.

If it is melting in the region of the battery/starter, you should not concern your self with an ignition main wiring short. A fuse would have blown way before, this is what we call a direct short.

Remove any fuse and relay starter related, or high amp fuse such as the alt fuse. replace the said wire and try again.

Question? Are there any aftermarket stuff installed? Remote starter? ETC.

If the ign fuse did not blow, again, you have a direct short.

Here is a snapshot of a 1999 sunfire. Same circuit as your 2001 cavalier.

I chose this one because it is very demonstrative of were you should look.

Screenshot (478).png
 

nickb2

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#4
If the circuit cannot ground out, that is the cause.

So, again, in simplest form I can describe, if the power "wire" is melted, it can't ground. You NEED to locate that bad ground.

I don't think I have anything else to say, beyond just rip it all apart and redo all the wiring. Clean every ground you can find to bare bone and use di-electric grease on all contacts and surfaces.
 

nickb2

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#5
Also, if it was a relay problem and the main + pos melted, that relay would have smoldered way before.

So that being said, I need to shovel more freaking snow.

Good luck and keep us posted.

:bat:;)
 
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#6
A dirty or loose connection may cause overheating to happen. Corrosion inside that end of the cable might also be a cause. Cracked electrical structure inside the battery is a third possibility.

Anything that reduces the capacity of the circuit to handle the required current will create heat at times of high current. Extremely high current will cause circuit failure.

If your car has two negative wires, and one is big, and one is little, and the big one quits doing it's job....the little one is going to get overheated.
 

billr

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#7
Got a picture? Regardless, my first thought was the same as Dan... a loose or corroded terminal (that big screw with the 5/16" or 8mm hex-head).
 

Gus

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#11
Well, have never seen a battery terminal melt....have seen acid leak, making it look like it melted....that butt connector you see going to the starter, is probably part of the campaign Nickb2 is referring to......

Electrical connections only melt, due to high resistance(bad connection).......usually see this at switches, relays, and connectors at motors/solenoids......if the connection is not clean and tight, it starts to arc, which increases the resistance and can cause neough heat to melt the plastic harness connector....

I see Nickb2 and Mobile Dan are still here, doing a good job....
 
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#12
Surge current when a starter is first engaged can easily exceed 1,000 amperes. Have yet to witness the battery terminal melt, but sure at the starter solenoid connection where the 12 V is taken off for the rest of the vehicles electrics was sure a mess. Bare copper terminals, starter is way at the bottom, and exposed to a bunch of road salt splash. Kind of gives the impression vehicles are made for the showroom and not for the roads we have to drive them on.

In doing short circuit tests on a fully charged battery, contained within a safe environment because they can explode, currents in excess of 3,000 amperes can be expected. Ha, don't try this at home.