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cable gets hot

 
spuddzmcgee
I love my Chevy Chevette!
Posts: 8
Joined: 10/09
Posted: 01/02/10 11:54 PM

I've been getting ready to start my engine for the first time and tonight my buddies noticed that the negative battery cable was getting really, really hot.  Like hot enough to melt the solder on it.  So my question is what could be causing this?  Our guess is something is grounded when it's not supposed to be, or grounded when it shouldn't.  Any input would be appreciated.  

Thanks, spudd  

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waynep7122
Everything in my driveway’s a Chevy
Posts: 556
Joined: 08/09
Posted: 01/03/10 10:36 AM

were you cranking the motor when it got hot??????

was the battery low on charge?? when you were cranking???/   is it possible that the starter wedged into the ON position..

starters do wear out..  they do go bad....   they can also have the long bolts that hold the starter together come loose.. letting the starter case move around..  you might if you have a conventional delco starter.. take it apart.. examine it for rubbing between the armature winding area and the pole shoes in the case.. if it does.. it will take tremendous current to make it turn..  it is also possible that the armature is bent..

new motors most of the time take a lot of starter power to make them turn..

have you set the distributer????? so it will start on the first try????

easier with an HEI type...   set the harmonic damper mark to 8 degrees before.. unless it is computerized  those get 15 before...  turn the housing so the reluctor teeth and the pick up coil teeth line up exactly...   if you have a chevy.... the rotor will be pointing at either the number one or number six spark plug wire position..    1843 6572


you might really want to think about thicker battery cables... and brass battery cable ends..   truck electrical shops make their own battery cables... and usually have brass ends that are soldered and crimped on...    they can also add wires to the battery end to run the car accessories and for the battery to body grounds...  

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spuddzmcgee
I love my Chevy Chevette!
Posts: 8
Joined: 10/09
Posted: 01/03/10 12:10 PM

yea, it was when i tried to start it that it got hot. battery's charged up too.  the starters working fine, or at least it sounds like it is. doesn't sound like its stuck or anything.  the solenoid seems to be disengaging properly.  the distributor is set, unfortunately it's points and i have the firing order right. could something with that old distributor be wrong and causing a short or ground somewhere?  

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waynep7122
Everything in my driveway’s a Chevy
Posts: 556
Joined: 08/09
Posted: 01/03/10 02:03 PM

points...   not hard....  again.. set the damper..  8 degrees as i recall on points chevys...

turn the key on...  rotate the distributer clockwise. a ***  then slowly clock wise until you hear the coil spark..  lock it there...

again.. the rotor should end up pointing toward the number one or number six spark plug wire in the cap..

you will have to pull the number one spark plug to see if the rotor is pointing toward the number one position when the compression stroke is reaching its top...

when the points are closed... the coil circuit is complete... when the points open... the circuit is broken.. the magnetic field created in the primary windings collapses through the secondary windings creating a high voltage spark...


one more thing... are you sure that the timing marks line up on the damper and pointer when the piston is at TDC



there is nothing  i like better.. than sticking a distributer in... bumping the engine around... tightening the bolt... standing up... reaching through the window.. and starting the motor..  on the first try.. without having to touch anything..  

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spuddzmcgee
I love my Chevy Chevette!
Posts: 8
Joined: 10/09
Posted: 01/03/10 02:55 PM

ok thanks. ill go recheck everything and make sure its lined up.  but should my negative cable still be running so hot?  

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waynep7122
Everything in my driveway’s a Chevy
Posts: 556
Joined: 08/09
Posted: 01/03/10 09:46 PM

when the engine is running.. it should not be hot from current passing through it...

when you crank the motor for more than 20 or 30 seconds.. it can get really hot..

if it is a cheep vinal covered cable.. and undersized... it could smoke..   i have seen them get hot enough from extended cranking..  that the insulation fell off...

i have also seen the battery cable ends melt...   i have seen a few of them get hot enough to melt part of the battery post..

once a cable is really damaged from overheating.. it really needs to be changed...

one more thing.. is there  any chance that there is a short to ground somewhere on the cables????? so when the starter is cranking.. most of the current is going straight to ground...

do you know anybody with a DC amp clamp..  that can read up to 400 amps DC???????/  

starters should not pull over 200 amps to start the engine cranking..  then drop to 175 to 150 amps..

if your engine is really tight ... or your timing too advanced... it will take a HUGE amount of power to crank the engine..  

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55Guy
Administrator
Posts: 1153
Joined: 07/06
Posted: 01/04/10 08:38 AM

How heavy a gauge is the battery cable? Just like with jumper cables, a light gauge battery cable will cause you trouble.

Where do you have the negative battery cable grounded to? The engine block? Frame?  

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spuddzmcgee
I love my Chevy Chevette!
Posts: 8
Joined: 10/09
Posted: 01/04/10 09:55 AM

its grounded to the block and the block to the firewall.  the extended cranking time could be why it gets so hot.  as for the distributor being too advanced, it's a possibility.  when i get some time im just gonna pull the distributor and put it back at tdc and start all that over again.  

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waynep7122
Everything in my driveway’s a Chevy
Posts: 556
Joined: 08/09
Posted: 01/05/10 09:31 AM

when i get some time im just gonna pull the distributor and put it back at tdc and start all that over again.  


wrong...

what we are talking about.. it the timing being advanced too much... like having the timing set beyond 15 degrees before top dead center... it will make the engine hard to crank... as the spark plugs are firing before the pistons come up...


question of the day... did you get it started... does it run...?????  

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spuddzmcgee
I love my Chevy Chevette!
Posts: 8
Joined: 10/09
Posted: 01/06/10 08:23 PM

no i havent had time to work on it yet.  i started back to school this week and its supposed to be balls cold here in oklahoma this weekend so i dunno if ill get around to workin on it or not.  

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spuddzmcgee
I love my Chevy Chevette!
Posts: 8
Joined: 10/09
Posted: 01/06/10 08:24 PM

so pullin the distributor would be a bad idea then  

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waynep7122
Everything in my driveway’s a Chevy
Posts: 556
Joined: 08/09
Posted: 01/07/10 09:21 AM

first... i really hope that you have coolant in the motor...  before it gets below 32F... i just saw the weather report... looks like you might get down close to 0F

how easy is the engine to turn with a long breaker bar???? do you have a torque wrench... beam type.. click type/????

put the 5/8 six point socket on the crank bolt.. see how much it takes to get the engine turning..  with a beam type.. you can just look at the scale...   with a click type.. you have to start at the lowest setting..    try it... does the torque wrench click before the crank starts to turn????   if yes... turn the adjusting knob up 10 pounds... keep going until it turns without the torque wrench clicking..   then back it off till it just clicks and it moves...  POST the numbers...


lets start from scratch...   pull the number one spark plug...    bump the engine around with your finger blocking the hole... when you get compression out ... stop..    bring the timing marks to 8 before top dead center without going all the way around with the crank...

pull the distributer cap....    which way is the rotor pointing...      if you have the distributer in right... and you are on the compression stroke of the number one cylinder...    standing in front of the grill... your rotor should be pointing like the hour hand on a clock... at 5 o clock... ( i hope that you don't have a digital watch.. this could be hard to do then)

with the rotor pointing at 5 o clock..   drop the cap back on... see that your spark plug wire that goes to the number one is right over the tip of the rotor...

now.. with the cap off...  grab the rotor... it will twist on the mechanical advance...   look at the points..  when you turn the rotor.. are the points contacts just starting to open when you are just starting to twist the rotor????  they should be,

with the crank balancer marks lined up up 8 before...

you can loosen the distributer hold down clamp...   turn the key to the on position without cranking the motor...

rotate the distributer clockwise.. a few degrees..  then slowly turn it counter clockwise until you hear the points spark.. you can also hear the coil spark.. this is usually done with the cap on..  

when the points are closed.. the coil is charged.. when the points open.. the coil discharges and creates a spark...  

if you can figure out exactly where the coil sparks when you are turning the distributer housing counter clockwise.. and lock it down there...    it should start without having to twist the distributer..

i do this every time i work on an engine.. its not hard..  its easy.. it makes you look like a superman if you can do this...

i love the looks i get when i drop a distributer in...   twist it a little..   reach through the window... turn the key... and the engine starts on the first try... after you get good at this... i get it so close.. i usually don't have to adjust the distributer...

i wish more people knew how to do this...  some engines are really really hard to get to the distributer...


perhaps... you should copy the text and print this...

wayne..  

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spuddzmcgee
I love my Chevy Chevette!
Posts: 8
Joined: 10/09
Posted: 01/07/10 11:04 AM

coolants already in. it was easy to turn it when it was on a stand. havent tried to turn it in the engine bay.
yea i was planin on printin this off before i got to the bottom lol.
thanks for the help, hopefully i get to go try this next week when it gets warmer.
thanks wayne  

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spuddzmcgee
I love my Chevy Chevette!
Posts: 8
Joined: 10/09
Posted: 01/13/10 06:37 PM

well it was warm enough for me to actually get out and work on it.  set it all up like all that, went to turn it over and my battery was sparkin at the posts.  so im assuming that some wire coating got melted somewhere and is causing a short. so now i get to hunt that down  

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waynep7122
Everything in my driveway’s a Chevy
Posts: 556
Joined: 08/09
Posted: 01/13/10 06:39 PM

one thing ... disconnect the alternator... see if it still sparks????? blown up alternators will cause all kinds of problems...  

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