Negative battery cable hot.

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Hiduster

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After sitting for about 2 months, I tried starting my ‘71 Duster 340. It was hard to start but after some starting fuild it started. After warming up the engine I turned it off and tried to disconnect the negative battery cable. I normally do this because I don’t drive the Duster. The negative battery cable burned my hand. It was extremely hot to the touch. Prior to this the car ran fine and the battery cable never got hot. Any help to fix this problem would be greatly appreciated. I normally start the car once a month. Could it be a bad ground? Bad battery cable? Bad battery?
 
Probably alot of cranking or the starter is starting to go drawing too much current. but could be a short but a dead short it would eventually burn the insulation off the cable youd see smoke.
 
Install a cut off switch between the negative cable in the battery. Don't rely on unbolting the terminal that takes too long in the event of an emergency.
 
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What all do you have for grounds and how clean are they? Do you use a batter tender to keep the battery fully charged?
 
Sounds about normal after cranking until the starter is almost fried. That's why so many guys have new cable ends on their leads, crank and crank until they melt right off...
 
As Minecar mentioned resistance = heat... Clean your battery cable and battery post....
 
IMHO

There could be a few things going on here.

  1. You cranked the engine more than normal
  2. The negative cable might not have been properly tightened
  3. There might be some corrosion on the terminal.
  4. You never feel it right after so much cranking and it always gets that hot


Reasons

  1. Per your statement you did a lot of cranking. IMHO cranking should be in short bursts, like a second or two at a time
  2. If you routinely disconnect the terminal perhaps you did not get it tight enough when you put it back on. Loose connection =resistance= heat
  3. If the terminals are continuously in contact little to no chance of corrosion buildup. If the terminal is removed the neg post and the terminal can/will build up corrosion
  4. Self explanatory, it's normal, you just never noticed it before.


I suspect that there is no electrical issues as that would melt other wires before getting the battery terminal hot.

Easy to check

With neg terminal disconnected and EVERYTHING in the car off, door shut etc.

Check voltage between the neg terminal Al and the negative battery post.

Should read the same on your meter as if the leads are not touching anything.


If it reads higher you have something consuming current. (Modern radio with a built in memory etc)

You can test the amps the same way. But if it is a large load you might blow a fuse in your meter.
 
Dana67Dart said:
IMHO

There could be a few things going on here.

  1. You cranked the engine more than normal
  2. The negative cable might not have been properly tightened
  3. There might be some corrosion on the terminal.
  4. You never feel it right after so much cranking and it always gets that hot


Reasons

  1. Per your statement you did a lot of cranking. IMHO cranking should be in short bursts, like a second or two at a time
  2. If you routinely disconnect the terminal perhaps you did not get it tight enough when you put it back on. Loose connection =resistance= heat
  3. If the terminals are continuously in contact little to no chance of corrosion buildup. If the terminal is removed the neg post and the terminal can/will build up corrosion
  4. Self explanatory, it's normal, you just never noticed it before.


I suspect that there is no electrical issues as that would melt other wires before getting the battery terminal hot.

Easy to check

With neg terminal disconnected and EVERYTHING in the car off, door shut etc.

Check voltage between the neg terminal Al and the negative battery post.

Should read the same on your meter as if the leads are not touching anything.


If it reads higher you have something consuming current. (Modern radio with a built in memory etc)

You can test the amps the same way. But if it is a large load you might blow a fuse in your meter.
Click to expand...
Thank you appreciate the suggestions.
 
Recharging the battery after it started would add to any of the above.
 
You live in a climate that is a haven for corrosion. Check bat terminal. If the neg cable got hot......then so did the pos cable....because the same current goes through both.
 
Besides the negative battery cable, how many other grounds does it have?
 
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