Melted a cable

Ok I have a new to me naa that I bought last year. Started right up and ran like a top every time I used it this fall. Generator started squealing and stopped charging the battery so I took it off and had it checked and had it rebuilt since it was shot. Put back on today reconnected the battery and tried to start it for about five minutes. Something started smelling hot so I quit and noticed that the battery cablewas just starting to smoke. It's a 6 V system with a 6 V generator and I had The battery positive ground. Everything should be hooked up exactly the way it was when I took it off. So what have i done wrong? Do I need to polarize the generator? It tried to start several times just wouldn't grab and fire up. I'm a little lost any help would be great thanks
 
Polarizing a generator (if done correctly) never HURTS, but that ain't your problem, with a hot BATTERY cable while trying to start it.

If there is a dead short, both the + and - cables would get equally hot, but you report the heat is in one place.

That indicates there's a poor/loose/dirty connection where the heat is!
 
Agreed, check connections. As said, motor Genny cause ot tests it and wont hurt it. Remove field wire at Genny. Jump Genny field and armature to bat hot with belt off and Gen should spin. Gen should be installed and grounded to chassis and matter installed for this test.
 
Firebyprolong,You say, reconnected the battery and tried to start it for about five minutes. Something started smelling hot so I quit and noticed that the battery cablewas just starting to smoke.

Check the battery cables as Bob stated,clean and tight-bright.
The points may br corroded since last fall.Check for spark by removing the coil wire from the distributor cap and hold it 1/4" from the block while cranking over with the switch on and check spark.
 
You should have OO size batt. cables for both sides of batt. A #4 or even a #2 will heat up a fair amount with prolonged cranking(current flow).
 
cleaned connections all tight and bright, insulation intact with no rub marks so no short to ground that I can find. Even made sure the points where in good shape .Hooked the battery back up and the cable and connection to the solenoid where painfully hot to the touch as soon as I turned it over. How exactly do I determine the field and arm poles on the gen?
 
Firebyprolong You say,the cable and connection to the solenoid where painfully hot to the touch as soon as I turned it over.
Well that tells you that the cable end has a bad connection @ the cable end.Replace the copper end solider it on w/torch if the rest of the cable is good,or replace the complete cable.Use 00 size best, or at least 0 size.Get it running first ,then fix the generator.The field and armature are marked on the generator with a F and a A and a G for ground.
 
You might want to recheck your Gen. , I'm wondering
if when they rebuilt the Gen. that they may have
rewired it as a NEGATIVE Ground instead of a
Positive Ground as it should be.

:>)
 
(quoted from post at 23:09:24 03/12/15) cleaned connections all tight and bright, insulation intact with no rub marks so no short to ground that I can find. Even made sure the points where in good shape .Hooked the battery back up and the cable and connection to the solenoid where painfully hot to the touch as soon as I turned it over. How exactly do I determine the field and arm poles on the gen?
orget the generator, as has already been said, it isn't the cause of melting battery cables. Five continuous minutes of cranking ought to make starter smoke & perhaps cable smoke, but I doubt that is what you intended to say. Even if you have poor 4 gauge light weight auto cable, a 2 foot length, at 400amps(low voltage, starter problems, etc. kind of current), then the power loss (heat) in that 2 feet of cable would only be 80 Watts (think light bulb with heat spread over 2 feet)..........that won't melt cable in a few minutes. So, ....get to looking for bad connections at/in cable terminations, anywhere possible. Make sure your battery is really providing ~4.5 to 5.0 volts during cranking. With a starter motor, low voltage translates to higher current. But forget the generator for now. As a matter of fact, if it will make you feel better, disconnect it & tape up lose wire ends!
 
It sure sounds like he is getting a direct short and I agree, sounds like the generator was rebuilt with a negative ground! If the solenoid and cable are getting that hot, that quickly it is a direct short.
 
As soon as you are energizing the solenoid the circuit is closed (connected) and the positive current flowing through ground is shorting into your incorrectly rebuilt generator that has a negative ground, causing a direct short. That is why just those cable and the solenoid are getting so hot.
 
Battery cables do go bad over time and you can not see that they are bad an most meters will not tell you either. So you either have bad cables or your starter is going bad either one or both will cause your problem
 
A generator does not car if it is + or - ground and will work either way depending on the V.R. Now an alternator on the other hand does care about the ground.
 

Which exact wire is burning up? If it is the actual battery cable than the genny has nothing to do with it.
If the short was at the genny those smaller guage wires would fry up before the battery cables. And I am quite sure that what ever size battery cables you have, they are heavier than the 12ga wire running at the genny.
 
(quoted from post at 12:30:53 03/13/15) You might want to recheck your Gen. , I'm wondering
if when they rebuilt the Gen. that they may have
rewired it as a NEGATIVE Ground instead of a
Positive Ground as it should be.

"Dr. Walt "It makes no difference to a generator positive ground or negative ground the generator is wired the same.What makes the difference is how it is polarized, positive ground or negative ground and its residual magnetization of the pole shoes.A generator needs to be polarized before engine start up if it has been removed and replaced to have the proper polarity.
 

It makes no difference to a generator positive ground or negative ground the generator is wired the same.What makes the difference is how it is polarized, positive ground or negative ground and its residual magnetization of the pole shoes.A generator needs to be polarized before engine start up if it has been removed and replaced to have the proper polarity.
 

O great one even a cheap meter these days is rite dag actuate...

I dunno what you have again'em did you forget how to use one and think no one else ever used one...

VM issues seam to be a issue you shy away from...
 

A direct short is gunna be a real smoker in short order ... Its not gunna take 5 min you can bet your sweet arse on that...
 
To the op, like said, probably as simple as a bad battery cable or end. (and 5 minutes of attempted starting tells you it's time to go thru the ignition and fuel circuit too....(5 revolutions should start it, and that's on a cold day...)

no need to guess, google
Starter Voltage Drop Test
and do some reading.
it's actually fun to ferret out that hiding bad cable/connection....aha..gotcha




(quoted from post at 22:54:08 03/14/15)
A direct short is gunna be a real smoker in short order ... Its not gunna take 5 min you can bet your sweet arse on that...
made me chuckle there Hobo. I've had a few dead shorts.
smaller wires just disappear...big cables..lol..bright red, billowing clouds of smoke as insulation melts....trying to keep your jacketed back to the battery as you cut the battery cable with big lopping pruners...great fun
 
Ok pulled out the multi meter and did some testing. It appears
the the VR is cooked. I seem to have a short to ground in the
VR. When I pull the batt connection loose from the VR boom
no short to ground. Pulled the cover off the VR an found the
white mark of death from where I let the smoke out. Next
question did I kill the VR by not polarizing the gen before I ran
it?
 
(quoted from post at 18:03:16 03/21/15) Ok pulled out the multi meter and did some testing. It appears
the the VR is cooked. I seem to have a short to ground in the
VR. When I pull the batt connection loose from the VR boom
no short to ground. Pulled the cover off the VR an found the
white mark of death from where I let the smoke out. Next
question did I kill the VR by not polarizing the gen before I ran
it?
here is more than meets the eye here. Those small wires connecting the batt & arm to VR & generator will act like a fuse & burn in two before the battery cables. Sure, firing up a gen that is polarized opposite the battery can short the cut out contacts in the VR and result in dumping battery supplied current into the generator. Usually makes generator hot & perhaps damage wires connecting to BATT & ARM. What is the rest of the story, as Paul Harvey used to say?
 

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