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Hot Rods Damage from reversed polarity?

Discussion in 'The Hokey Ass Message Board' started by 5brown1, Aug 28, 2015.

  1. 5brown1
    Joined: Apr 13, 2008
    Posts: 196

    5brown1
    Member

    I have a friend with a 37 ford with the flathead V8. The battery has been installed with a negative ground rather than the factory positive ground configuration. His amp meter is naturally reversed. He says it is running and so is reluctant to change the polarity.

    My question is: What harm would it possibly do to the electrical components of the car? I know the starter and light bulbs will function but what about the generator he just replaced, coil, voltage regulator, etc.?

    Thanks,
     
  2. plym_46
    Joined: Sep 8, 2005
    Posts: 3,935

    plym_46
    Member
    from central NY

    not a problem, heater fan running backwards??? He should check his coil and assure it is wired to reflect the proper terminal going to ground. Usually has no effect on other things, but if the coil is backwards, under high load or high rpm it might breakdown a bit.
     
  3. stude54
    Joined: Jan 9, 2008
    Posts: 47

    stude54
    Member
    from michigan

    If he has a voltage regulator it will need to be polarized again.
     
  4. plym_46
    Joined: Sep 8, 2005
    Posts: 3,935

    plym_46
    Member
    from central NY

    the generator gets polarized not the regulator. I don't think he stated he was changing back.
     
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  5. Kevin Lee
    Joined: Nov 12, 2001
    Posts: 7,406

    Kevin Lee
    Super Moderator
    Staff Member

    Did he swap it accidentally or did a previous owner? Sure seems like you would at least need to swap the +/- leads on the coil to even get it to run.

    The battery gauge should run the correct way if you just loop the wire through it in the opposite direction. I guess everything else would be fine?
     
  6. Same answers that you got on the AACA site for the same question
     
    LOST ANGEL likes this.
  7. Gene Boul
    Joined: Feb 9, 2006
    Posts: 807

    Gene Boul

    Doesn't it just make sense to reverse the connections. However, if he's reluctant to change the orientation of the cables then there are more problems to come...
     
  8. JonF
    Joined: Mar 6, 2010
    Posts: 169

    JonF
    Member

    if the amp meter is moving it is charging so no need to polarize anything.
     
  9. JonF
    Joined: Mar 6, 2010
    Posts: 169

    JonF
    Member

    fan in the heater won't run backwards either and the starter is fine on reversed polarity too.
     
  10. What was the point in reverse polarity?
     
  11. Rusty O'Toole
    Joined: Sep 17, 2006
    Posts: 9,068

    Rusty O'Toole
    Member

    Probably be ok if he doesn't have a radio. Should swap the leads on the coil for best spark. A coil will work "backwards" but not as well.
     
    Bobp likes this.
  12. txturbo
    Joined: Oct 23, 2009
    Posts: 1,771

    txturbo
    Member

    A negative ground battery can be used in a positive ground system. A battery can be reversed if needed. Hook a sealed beam to the battery and discharge it completely....then hook the battery charger to it with the polarity reversed and charge it up backwards.
     
  13. One of the most ill advised posts that I've read in quite a while. Firstly, there is no such thing as a "negative ground battery". A battery is just a battery. It has no polarity. Why in the hell would anyone try to, purposely, charge a battery backwards???? Just switch the cables, coil leads and re polarize the generator and you're done
     
    WDobos, LWEL9226 and Budget36 like this.
  14. dirty old man
    Joined: Feb 2, 2008
    Posts: 8,480

    dirty old man
    ALLIANCE MEMBER

    X2 on all Carl said, including the "ill advised" part, and that's being charitable!!!!!!!!!!!!
     
    WDobos and LWEL9226 like this.
  15. Hahahahahahahahaha,funniest shit I've read here lately....( 6 munce ago,I couldnt even spell mechanic,now I are one)
     
  16. txturbo
    Joined: Oct 23, 2009
    Posts: 1,771

    txturbo
    Member

    I just said it could be done....a helper of mine hooked a dead battery from his motorcycle up backwards and it charged up fine. Didn't work so well in his motorcycle. If it didn't matter then batteries wouldn't have a plus and minus sign next to the posts.
     
  17. txturbo
    Joined: Oct 23, 2009
    Posts: 1,771

    txturbo
    Member

    If batteries didn't have polarity they wouldn't mark them. It's true the battery doesn't care, but some of the other parts in the system do.
    I don't know why anyone would do it on purpose, but it can be done.
     
  18. Fine. Then what is the difference between a "negative ground" battery and a "positive ground" battery??? Rather that keeping anyone in suspense, the answer is, none, because the batteries do not have polarity. Polarity only comes into play when a circuit is made. I don't think you quite have a grasp of what the term actually means
     
  19. txturbo
    Joined: Oct 23, 2009
    Posts: 1,771

    txturbo
    Member

    I do....it just depends on the context. By itself a battery doesn't but if it's part of a system it does.
    It's the same with electron flow....you can argue about which way it flows all day long.
     
  20. Mike51Merc
    Joined: Dec 5, 2008
    Posts: 3,822

    Mike51Merc
    Member

    Sir, all you need to do is reverse the connections, and if you have to, lift up the battery and turn it around to make the connections fit. There's no such thing as a negative or positive ground battery. It is the pole's connection to ground that makes the ground.
    Looking for a positive ground battery is like looking for a left-handed screwdriver.
     
  21. txturbo
    Joined: Oct 23, 2009
    Posts: 1,771

    txturbo
    Member

    I agree....that's what I did on my positive ground tractor. I was just saying....if there is a need (which I've never found one) it can be done and that's how you do it.
    And now it's permanently documented for generations to come in case someone ever finds a reason it needs to be done.....unless Ryan deletes it.
     
  22. I suppose I could quote your original post, where you talked about negative ground batteries.:rolleyes:
    In a DC circuit, electrons flow from negative to positive. Learned that at welding school. DCEP or DCEN. I won't argue about it though because I'm correct;)
     
  23. txturbo
    Joined: Oct 23, 2009
    Posts: 1,771

    txturbo
    Member

    Yes...that's one theory.
     
  24. Mike51Merc
    Joined: Dec 5, 2008
    Posts: 3,822

    Mike51Merc
    Member

    It can be done, however for chemical reasons too complex to detail here, the battery will soon suffer and die from a short and degenerative death. It will essentially eat itself alive.
     
  25. Budget36
    Joined: Nov 29, 2014
    Posts: 3,259

    Budget36
    Member

    I believe TxTurbo (in regards to flow) is speaking of Conventional vs Electron flow, guess I was awake in class that day...
     
  26. 55Brodie
    Joined: Dec 15, 2008
    Posts: 746

    55Brodie
    Member

    Reverse the coil and ammeter connections and roll with it.
     
  27. I got to agree with this guy. btw from my understanding negative on The coil needs to be to ground. regardless. (keep in mind I'm a 65-year-old person that still very much learning.) just polarize the generator again. negative on coil to the ground on the battery. which what I've heard so far should be a positive ground.
     
    Last edited: Sep 3, 2015
  28. Hey Txturbo...that electron flow?.unless its a queer electron.then all it will do is "blow" fuses
     
  29. slack
    Joined: Aug 18, 2014
    Posts: 523

    slack
    Member

    Please Mr Le Fong, take me to Kiek in de Kock. Ahhhhhhhhh, sweet relief.
     
  30. plym_46
    Joined: Sep 8, 2005
    Posts: 3,935

    plym_46
    Member
    from central NY

    I have seen a vehicle that runs both a 6 volt positive system, for the engine, and standard lighting, the 2 speed rear end, and a 12V negative system, for auxiliary lights, various radios, winches, the starter for the generator /welder, the starter for the heavy duty pump. Under the hood it has a generator for the 6V and alternator for the 12V and both battery ground straps go to the engine block, the cab and service body are grounded to the frame and all accessories whether 6 V positive or 12 V negative are grounded as they normally would be.

    That, I am sure will blow a few head gaskets a people try to wrap their noggins around the concept.
     

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