Blew the post off the battery

[Abram]

I tried to fire up my 8640 after putting new batteries in it, the starter kept turning over when I turned the key off and then I heard a pop. Turns out one of the battery posts blew off. What went wrong? I'm guessing the starter had a short...not sure why the starter kept cranking. Any suggestions? Please help.

 

[msb]

Sometimes a plugged vent in the cap will cause this, but in your case I would guess it was an electrical spark caused when your solenoid fried the contactor.

 

[johns48jdb]

i have an ih 574 that does the same thing. mine usually just does it if the battery isn't up to snuff. i put a cut off switch in the ground side on the battery cable that i can get to fast to shut the juice off. the starter will disengage then. i'd love to know the answer to the problem about the starter that keeps running myself. i can't believe that a new battery would blow up like that. for that to happen there has to be a spark. you could have had a loose connection at that post. no way to tell now, but was there any chance that a strand of wire from the cable got close to the battery tray and made contact with it.

 

[Abram]

Thanks for the help. It had to be a spark from almost a direct ground or ark. I'm taking the starter and selonoid in to get it tested. Also, Someone told me I can drill and tap a bolt into the blown off battery post...I think the post should be around 2" deep and sounds worth a try rather then fork the money out for a new battery as well.

 

[Abram]

The closest metal (the battery tray)for the spark to jump was 1/4" from the post that blew off. I also noticed heat in the cable connecting the two 6 volt batteries. It was one of the terminals that this cable was on that blew off. The rubber insulation on this cable was gooey (soft and warm) when I checked it after the the incident.

 

[buickanddeere]

High resistance battery connection and melted the post off.

 

[johns48jdb]

you didn't have the batteries hooked up wrong did you by chance? thats something i would do because i'm always in a hurry.

 

[Abram]

No, they where hooked up correctly except the terminal may have been loose. I just got the starter and seloniod checked out and they turned out fine. I only have 2 ideas now. The batteries arched 1/4" to gound out or a possible loose therminal had enough resistance to cause things to heat up on the post and blow it off. What do you think? My starter guy suggested I check a relay to see if it went bad causing the starter to keep turning over by itself. Otherwise I am stumped on this one.

 

[Anonymous-0]

Starters won't keep running unless their getting juice. A solenoid or key switch somewhere stuck closed.

I had the starter solenoid/linkage stick closed once on a NEW starter on a 4020. I took it back and the retail shop replaced it.

Perhaps solenoid contacts welded together--from overload, weak battery/conection, prolonged cranking??? I've had that happen with mechanical contacts on a JD 60. (Tractor had troublesome PTO clutch, and operater tried to start engine with PTO clutch engaged and under load.)