Smoking Battery Cables!

[BB_TX]

<font color=blue>will cause resistance which will increase amp draw </font color=blue>
This is an often stated misconception of electricity. An increase in resistance causes a decrease in current flow. Ohm's law is V=IR (voltage = current times resistance). Or to rearrange, I=V/R (current = voltage divided by resistance). As resistance increases, there is a proportional decrease in current.
A bad connection does cause heating because of a voltage drop across that connection point. This can be thought of as the power loss across that connection. Power(in watts)=VA (volts time amps). Also Power=I(squared)R (current squared times resistance). If the connection were perfect (no resistance) there would be no power loss. As the resistance increases, the power loss is multiplied by the square of the current. That loss grows rapidly as the resistance increases, and thus the heating.
Not trying to stir anything up, just want to clear the issue./w3tcompact/icons/smile.gif

 

[Soundguy]

Actually, a higher resistance will lower the current flowing through the circuit... but a coroded cable connection will make the cable drop a good amount of voltage across it, making it more of a resistor than a conductor... and it will start disipating a decent amount of power as heat.

Someone probably put lawn mower cables on it or something similar.

Soundguy

 

[hazmat]

OK I'm an idiot and forgot that Voltage = Current * Resistance.

I was trying to quantify an experience I had with a loose connection getting hot. We had an inverter put in my dad's boat. They wired a switch so you could choose between shore power & inverted power (both 110V). They didn't tighten up on the connection & when turned on, the wire got hot & started to melt the insulator. When the connection was tightened up, no problem.

 

[boustany]

There are several likely reasons why your battery cables would be smoking:
1) undersized cables, corroded cables, etc., which don't have the current handling capacity and are therefore basically being heaters;
2) Too much load as a result of a starter motor malfunction (or load on the engine), which would put excessive draw on the battery and overload the cables
3) Undervoltage at the battery, which would not allow the starter motor to operate correctly and spin up to speed. This could be due to a defective battery, or one with insufficient cranking power.

2 & 3 are as a result of the fact that electric motors draw a lot of current before they get up to speed due to a lack of 'back emf'. A stalled motor, or close to it, is basically a short circuit. Undervoltage doesn't deliver enough power to spin the motor up, and surprisingly enough can lead to a burnt out motor due to excessive current draw. I would try replacing the cables (which are probably shot by now anyway), testing with a new battery (which can be borrowed) and then replacing the starter.

The worst possible thing is that the tractor engine is putting too much load on the starter. Hope its not that.

Tell us what the fix was!

 

[turnkey4099]

And don't forget that the ground cable has connections on -both- ends. I had much the same problem and after many sessions trouble shooting I found the problem was the connection at the other end of the ground cable, not the battery end.

Harry K

 

[Soundguy]

You wouldn't believe how many ground connections I've seen made to a frame, etc, and the paint wasn't removed.. allowing only minute conduction ( if any ) threw the bolt face, etc.

Soundguy

 

[chuckokie]

Ok so I replace the postive battery cable, negative battery cable, the battery and the cable to the starter and a resistor and it still won't start. It kind of whines and the resistor gets pretty hot. I've checked all over looking for a short and don't see one. Any other hints. By the way I'm a novice at this and this is my first tractor.

 

[Don87]

Ok so I replace the postive battery cable, negative battery cable, the battery and the cable to the starter and a resistor and it still won't start. It kind of whines and the resistor gets pretty hot. I've checked all over looking for a short and don't see one. Any other hints. By the way I'm a novice at this and this is my first tractor.

Congratulations, you are the winner...........you just replied to a 9 year old thread. Heck..........you even beat my record by 2 years:laughing::laughing::laughing:

Find the appropriate forum for the tractor that you own. Please list your location, model and year of your tractor........then post the problem.

You will get much faster responses and fixes this way.:thumbsup:

And welcome to TBN

 

[eastexan]

What kind of tractor do you have?