Battery grounding on vintage allis chalmers

rpapka

New User
I have a vintage allis chalmers model B tractor. Can you tell me if it is a positive ground for the battery? I have been trying to jumpstart it from my pickup truck and hooking + to + and - to - but it doesn't seem to work. Many sparks fly and the battery cables get very hot. Any suggestions would be greatly appreciated. Thanks
 
(quoted from post at 13:33:30 08/03/15) I have a vintage allis chalmers model B tractor. Can you tell me if it is a positive ground for the battery? I have been trying to jumpstart it from my pickup truck and hooking + to + and - to - but it doesn't seem to work. Many sparks fly and the battery cables get very hot. Any suggestions would be greatly appreciated. Thanks
re you connecting a 12v battery to a 6v battery?
 
Yes it is positive ground. Sounds as if it is still 6 volts and you are trying to use a 12 volt jumpstart.
 
You had better quit before you blow up a battery & hurt yourself. Find somebody that knows what is going on.
 
You are lucky the batt didnt explode getting acid in your face you dont use 12v to jump a 6v system hardf to tell just what you mite have burned up. Take the starter to a shop and let them refresh it
 
Your lack of info makes it hard for us to help you help your self.
#1 if it is still 6 volts and your trying to jump it with 12 volts STOP now before you end up in the hospital.
#2 yes it should be + ground if 6 volts.
#3 to jump start a 6 volt tractor with 12 volts you hook up your ground form the truck to the tractor frame and you then take the + cable and go to the stud on the starter to spin it over. If the 6 volt battery is dead it will not start if it has a distributor on it since you need a hot battery for spark
 
It is done everyday. You need to connect the cables correctly [use your positive cable as ground on tractors with positive ground] and hook to the hot wire on the starter terminal first and then the ground. Don't let the armchair experts fool you with their scare stories. In the days before 12 volt was common, if you called for help in getting your car with 6 volt system started the service truck would show up with a 12 volt battery AND GIVE YOR VEHICLE ONE HECK OF A BOOAST. At all of the big farm auctions that I attend, and I have been to many, they have a cart or trailer with many booster batteries and they sometimes boost the tractors with 18 or 24 volts and I have never seen any battery explosions.
 
Old you are right about the connection unless it is a positive ground and then you need to hook the positive from the truck to a bolt on the tractor and then put the negative clamp to the battery post on the starter. And now I just told you the connecting order backwards, Hook the grounding cable [whether positive or negative] on last so that any spark is away from the battery.
 
JUMP STARTING TRACTORS

1) Regardless if the tractor is Pos or Neg grounded, you always jump one battery to another + to + and - to -

2) DO NOT make the final spark producing jump connection near the top of a battery where explosive gasses are present

3) DO NOT jump a 6 volt battery from a 12 volt battery, good way to blow up a battery.

4) I have successfully jumped a 6 volt tractor using a 12 volt battery however, but I ONLY jump the starter motor direct so it and NOT the 6 volt battery nor the 6 volt electrics see 12 volts, ONLY the starter motor. That way I DO NOT jump the battery but only apply voltage to the starter motor.

5) The way I jump start a tractor so there's no sparks near battery top where explosive gasses are present, is to make the final frame/jump ground connection last down away from the battery as far as possible.

6) If you jump a Pos ground tractor with a Neg ground vehicle, still + to + and - to - HOWEVER dont let the tractor and vehicles touch each other.

Im sure I missed a few points so others can add to this

Hope this helps, post any questions

John T
 
"4) I have successfully jumped a 6 volt tractor using a 12 volt battery however, but I ONLY jump the starter motor direct so it and NOT the 6 volt battery nor the 6 volt electrics see 12 volts, ONLY the starter motor. That way I DO NOT jump the battery but only apply voltage to the starter motor."
How did you or might you do this on an old Farmall where the starter motor connection is totally enclosed inside the switch mounted on starter motor?
 
If you were determined you could take out the
couple of screws holding the pull switch on the
starter. Under it is the power lug. I hook on a chain
and pull it, though.
 
Ifyour going to the starter it does not matter which way you hook it up the starter will still spin the same way no matter what. As for hook a 12 volt battery to a 6 volt one not a good thing to do and if you do not believe me tell the guy I knew that lost his eye site it is a good and safe thing to do. Battery exploded and that was the last thing he ever saw
 
JMOR, good question heres the answer:

In my many years as a used tractor dealer I had to jump start literally hundreds of them grrrrrrrrrr lol My method above in which I jump started 6 volt tractors using a 12 volt battery ONLY works on tractors with electric solenoids or mechanical push switches (like many IHC or other brand tractors with push switch on pedestal) where both the BAT and Starter post were exposed and readily available and unfortunately not so handy on saddle mount push mechanical switches with the copper starter post button hidden underneath. On such a starter you would have to remove the mechanical push saddle mount switch to get at the copper post but that's NOT recommended due to sparks and hard to get a good contact.

Best wishes, hope this helps and answers your good question

John T
 
Yep, the mechanical saddle mount push switches aren't handy to by pass jump as the mechanical 2 post (BAT and Starter)pedestal etc mount push switches (like IHC and many others used mounted somewhere) or solenoid starters.

John T
 
The way I have done it for decades probably has little risk, but probably not zero risk. With neg booster batt jumpered to neg tractor cable connection at starter switch (common to neg batt terminal), then pull (engage starter) start sw rod, then while it is trying to turn engine, I connect pos jumper to frame, thus applying 12v to starter & 6v battery while fully loaded by starter. Remove jumper to frame before releasing start switch. Never measured it, but with near dead battery, starter load & jumper cables/clamps losses, it probably isn't overvolting the 6v battery by much & for a very short time. Works for me.
 
(quoted from post at 17:42:03 08/03/15) The way I have done it for decades probably has little risk, but probably not zero risk. With neg booster batt jumpered to neg tractor cable connection at starter switch (common to neg batt terminal), then pull (engage starter) start sw rod, then while it is trying to turn engine, I connect pos jumper to frame, thus applying 12v to starter & 6v battery while fully loaded by starter. Remove jumper to frame before releasing start switch. Never measured it, but with near dead battery, starter load & jumper cables/clamps losses, it probably isn't overvolting the 6v battery by much & for a very short time. Works for me.

very similar to what I do on my Farmalls.
That on/off switch for the main cables on a battery jumpstart pack are great for your method.
hook everything up, get it cranking(or trying to), turn the switch on the pack, it starts, turn the pack switch off. (slick, but requires deft hand movements ...or 4 hands)

to the original poster......listen to the guys...why poke a lion with a stick....I've had a battery explode before (sparks..truck).....if I can avoid the tiniest chance of it happening again...I will
 

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