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Subject: Jumping a battery

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Larry    Posted 11-09-2018 at 01:23:42 [URL] [DELETE]        [Reply] [Email]  
  • Jumping a battery
  • I'm getting a Ford NAA and was told that It has been converted to 12 volt. The battery is weak and will probably need to be jumped. (I won't have time to charge it on the
    delivery truck) What is the best way to jump it using my 2003 neg ground truck

    Larry    Posted 11-09-2018 at 23:52:29 [URL] [DELETE]        [Reply] [Email]  
  • Re: Jumping a battery
  • Thanks to all for your help. When the truck rolled up, as expected, battery was dead. Noticed that the neg battery post was higher than the positive. Closer inspection revealed that it was broken and loose. I decided it would be best just to get a new battery rather than risk an explosion.

    Tim Daley(MI)    Posted 11-10-2018 at 08:41:47 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Jumping a battery
  • Good call. Was the battery secured down with something? I see many N's with batteries not with hold downs. When stationary they are fine but as soon as you go to work, the bouncing in the fields and such can cause them to short out against gas tank or hood. 12V is GRP 25 or 35. Verify all the rest of the wiring is correct B4 connecting the new battery up.

    Tim Daley(MI)

    Bruce (VA)    Posted 11-09-2018 at 07:31:56 [URL] [DELETE]        [Reply] [Email]  
  • Re: Jumping a battery
  • See tip # 43

    Then find out why the battery is dead; see tip # 49 to check the battery.

    Tim Daley(MI)    Posted 11-09-2018 at 06:01:32 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Jumping a battery
  • Don't rely on what someone else has told you. Verify things for yourself. A 6-VOLT battery will have 3 CELLS, a 12-VOLT battery will have 6 cells. Do you have a VOLT/OHM METER? A simple voltage test static will tell you if it is charged or not. Get battery tested at a starter shop or local auto parts store. If it is indeed a 12V switch over job, then the generator and voltage regulator are removed from the circuit altogether and a 12V alternator is then used. The wiring gets changed too. See JMOR's WIRING PICTOGRAMS:

    Tim Daley(MI)

    TheOldHokie    Posted 11-09-2018 at 05:44:33 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Jumping a battery
  • Plus to plus and negative to negative. Grounding makes no difference as long as you do not allow the vehicle chassis to touch.

    Bruce(OR)    Posted 11-09-2018 at 09:35:16 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Jumping a battery
  • That's interesting.
    Jumping vehicle batteries before plastic bumpers were to smack the bumpers together and get out the bumper jacks. Connect the bumper jacks to the pos batt terminals, hold the jacks together and start the dead car.
    You never did that, huh?

    TheOldHokie    Posted 11-09-2018 at 10:07:12 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Jumping a battery
  • Nope - I was a Boy Scout and always prepared. If you give it a little thought you should see why that is not going to work with vehicles/machines that have opposed earth wiring.


    Bruce(OR)    Posted 11-09-2018 at 22:12:51 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Jumping a battery
  • Most cars by the 60's had gone to 12V neg ground with metal bumpers.
    I suppose if there was a car with pos ground 12V and only the bumper jacks available with no cables, it would be possibles to switch the cables on one vehicle and jump the dead one using metal bumpers. The only thing being that you could not start the vehicle with the crossed cables until it was hooked correctly again.
    Then again, being a boy scout means you had jumper cables at all times.

    Jack - Iowa    Posted 11-10-2018 at 07:52:54 [URL] [DELETE]        [Reply] [Email]  
  • Re: Jumping a battery
  • I second poderac.

    Had an attendant reverse charge a battery one time ('35 Ford) Started fine but the Ammeter read backwards.

    Had him discharge it and recharge, all worked and it was the strongest battery I ever saw.

    poderac    Posted 11-10-2018 at 07:34:14 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Jumping a battery
  • ""The only thing being that you could not start the vehicle with the crossed cables until it was hooked correctly again. ""

    Wrong there, Bruce. I bought a "57 Ford that was positive ground 12 volt. The dealer did not know it and put the battery in backwards. It started and ran fine, but had to charge the battery every other day until I found the problem and reversed the cables.

    Jmor    Posted 11-10-2018 at 22:04:33 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Jumping a battery
  • By 57 those fords should not have been positive ground. Somebody been messin!

    Tony C    Posted 11-12-2018 at 19:15:00 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Jumping a battery
  • I believe Ford changed the polarity in '56 when they began installing 12V systems.

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