1961 battery cables getting hot

[Sargent_Arthur]

Hello, I went to drive the car last month and noticed the battery cables were getting extremely hot to the point the car wouldn't start. I did a small bit of research and ended up replacing the voltage regulator. I soon found out that, that wasn't my issue. It's been sitting for awhile now. Today I made sure the voltage regulator was working. It seemed to be. I turned the key for approximately 2 seconds and the positive battery cable caught fire. I was able to put it out with out hurting anything else.

Now my question still stand on what is causing the battery cables to get so hit that they are able to catch fire??? I'm completely dumbfounded on the fact of two seconds of power my cables pulled so much power to catch flames.

 

[ICON 56]

Did you check the ground wire to the motor base and feel the heat. Was everything turned off while the car was on. Was the battery hot. Try another battery.

 

[Sargent_Arthur]

Did you check the ground wire to the motor base and feel the heat. Was everything turned off while the car was on. Was the battery hot. Try another battery.

The battery ground isn't in exactly the best spot. I was considering that. But as the car has ran and drove after I moved the ground. It made me think twice. I still wonder about that. It's grounded on a bolt connected to the suspension on the engine bay. The key was turned for 5 sec at most. I did crank for a micro of a second. I was trying to test the voltage regulator when the positive cable abruptly caught fire.

 

[cokefirst]

you have a dead short. It is obviously in a circuit that is only hot when the key is on. Does it do the same thing when it is in accessory position? If so, it may be tougher to trace. It is also obviously on a circuit that is not fused or you have a short at your fuse box. This is going to require someone to trace the short. You will need a pulse circuit energizer only allows current flow for momentary periods then goes on and off. I would first look for blistered wires as a short like this will defiantly destroy wires.

 

[Tom Alpers]

Does the starter sound like it's working normally? If not, it could be the starter is drawing way too many amps. Normally it draws about 200 but bad one's might draw twice that much. Nothing else on the car draws enough to make the battery cables get hot in normal use. If something else in the car was drawing enough to make the heavy battery cable get hot then there should be some other smaller wires melting under the load. Bad connections or badly corroded wires inside the cables can get hot. If you see no other things to do I would at least go get a brand-new cable to replace the one which is getting hot, perhaps it's internally corroded or the crimpled terminals are bad. Also make sure wherever it's connected is a good clean tight connection.

 

[Mrjagrock]

It may be your starter is pulling too much voltage, but the ground does not sound good. I have replaced both cables with, non OE, 2.0 gauge cables- Plenty of juice getting to the starter.

 

[74 Harley]

How about you post a picture? The negative cable from the battery should go directly to the engine block. You didn't accidentally ground the wire coming off the solonoid did you?

 

[Sargent_Arthur]

Does the starter sound like it's working normally? If not, it could be the starter is drawing way too many amps. Normally it draws about 200 but bad one's might draw twice that much. Nothing else on the car draws enough to make the battery cables get hot in normal use. If something else in the car was drawing enough to make the heavy battery cable get hot then there should be some other smaller wires melting under the load. Bad connections or badly corroded wires inside the cables can get hot. If you see no other things to do I would at least go get a brand-new cable to replace the one which is getting hot, perhaps it's internally corroded or the crimpled terminals are bad. Also make sure wherever it's connected is a good clean tight connection.

So I'm starting with the ground being in a bad spot. I didn't have the starter on long enough to see if it was good. I'm not too worried about the starter being bad, as I replaced it last year. Where is the spot where it bolts to the block? I replaced the negative cable when I bought it. The bolt stripped and so did the internal thread and I never got to fix it. I now two years later cannot remember where it was originally grounded to.

 

[Sargent_Arthur]

It may be your starter is pulling too much voltage, but the ground does not sound good. I have replaced both cables with, non OE, 2.0 gauge cables- Plenty of juice getting to the starter.

So my test was just redone and I believe it's the starter, doing exactly this pulling too much juice. Bc my cable are normal until I try and start the car, then they instantaneously melt.

 

[doug7740]

So my test was just redone and I believe it's the starter, doing exactly this pulling too much juice. Bc my cable are normal until I try and start the car, then they instantaneously melt.

The first step to test if a starter is bad is ensuring the car battery is fully charged and the engine is at normal operating temperatures. A battery with low voltage might show a higher starter draw. Also, make sure that the cables and terminals are in good condition. This would rule out starter issues caused by low battery voltage.

Use a voltmeter and ammeter and follow the instructions below:

1. Unplug and ground the coil wire that goes to the distributor cap so that the engine does not start while you’re checking the starter.
2. Connect the voltmeter on the battery’s positive and negative terminals.
3. Put the amp clamp of the ammeter around the positive cable.
4. Crank the motor and take note of the amperage and voltage.
5. Check your car’s service manual for the starter draw test specifications and see if your measurements are in specifications.

A V8 engine would require a lot of power to start. For gasoline V8s, the minimum amount is 300A, If the engine is cold, a V8 would need around 720A.

If the engine cranks slowly and draws excessive current, there is a problem with the starter. This is most likely caused by faulty starter brushes, an engine blockage, or broken insulation.

doug7740
1955 Thunderbird Blue

 

[Tom Alpers]

After years of fiddling with hooking up ammeters in series with the battery and other equipment to do testing I finally broke down last year and bought a clamp on AC/DC meter. Should have bought one years ago. Makes checking amp draw to everything so much easier and particularly to measure the amp draw for the starter and the output of generator/alternator. The one I bought is the link below and it will use bluetooth if you wish to display readings on your phone.. which means you can hook it around the negative battery cable and measure the amp draw looking at your phone while sitting inside the car and turning things on and off. The meter also does all the usualy voltage and resistence tests with test leads.

https://www.amazon.com/gp/product/B08PBFJR5G/?tag=thunderbirdforum-20

 

[Ward 57]

After years of fiddling with hooking up ammeters in series with the battery and other equipment to do testing I finally broke down last year and bought a clamp on AC/DC meter. Should have bought one years ago. Makes checking amp draw to everything so much easier and particularly to measure the amp draw for the starter and the output of generator/alternator. The one I bought is the link below and it will use bluetooth if you wish to display readings on your phone.. which means you can hook it around the negative battery cable and measure the amp draw looking at your phone while sitting inside the car and turning things on and off. The meter also does all the usualy voltage and resistence tests with test leads.

https://www.amazon.com/gp/product/B08PBFJR5G/?tag=thunderbirdforum-20

That is an excellent diagnostic tool. Most don't know about it or pass it off as a shade tree mechanic not willing to buy a meter they will only use once or twice and clog up their tool box or justify the expense to the other half. I have no idea if they rent something like that.