Smoking Battery Cables!

[Anonymous Poster]

hi,

i have a problem with my fiat 70-66DT, it doesn't start easily due to bad cranking. and the positive battery cable gets really hot and sometimes starts smoking!! could it be incorrect cable sizes?? the heat/ smoking is a sign of resistance isn't it?
any help would be greatly appreciated!

regards

gareth

 

[s1120]

Sounds like a bad connection to me. Try removing the cables, and cleaning up where they attach. I bet that will work.

 

[mbsil]

Check the obvious stuff...corroded battery clamps (connectors), etc. Corrosion will "wick" its way up a cable.

I've seen corrosion travel 4 feet down a wire before.

Test the cable with an ohm meter. Anything over a couple of ohms on a cable this short means that the cable needs replacing as it is completely infiltrated with corrosion.

 

[RoyJackson]

"the heat/ smoking is a sign of resistance isn't it?"

Yepper!! You've got too much resistance on the line. This is your power (hot) lead, of course.
Have you added anything to your electrical system...more lights, by chance? Or higher wattage bulbs?
It could well be corrosion, as the other folks mentioned. I would replace the cable in it's entirety...ASAP! Before your tractor catches fire...

 

[bgott]

Do a voltage drop test. Set a DVOM on dc and touch on lead on the positive battery terminal and the other lead on the starter post. Crank the tractor and see how much voltage the meter shows. You will drop 3 or 4 volts with that much amperage going through the cable without any problem, I'll bet you show 6 volts or better. This loaded test is way better than a resistance test, all it takes is one connected strand in the cable to show zero ohms.

 

[BB_TX]

Corrosion will cause heating, but the heating would be at that point in the connection, not the cable itself. I would guess either the cable has been replaced with an undersized cable. Or the cable has a partial break somewhere under the insulation. Definitely replace the cable.

 

[WVBill]

Could be a combination of things: Maybe it's hard to start due to a weak spark (if gas engine) or something. Cranking it for a long time will heat up the battery cable. I had that happen on my motor home once and nearly melted the lead post connector on the cable in the process. When they say don't crank for more than 10 seconds (or whatever) between cool down cycles, I found out the reason...

 

[hazmat]

A loose connection will cause resistance which will increase amp draw which causes the wire to heat up.

 

[Anonymous Poster]

thanks guys,

my guess is that when we bought the tractor, they replaced the old battery cables for new thinner ones. they look new and cheap. another thing that i noticed is that both cables get hot, not only the positive one! corrosion is another problem i have. i will replace both cables with thicker ones and see!!

thanks for all the replies!!

regards

gareth

 

[Gomez]

<font color=blue>another thing that i noticed is that both cables get hot, not only the positive one!</font color=blue>

Makes sense, they are both carrying the same amount of current./w3tcompact/icons/smile.gif