Backwards alternator?

Discussion in 'General IH Tech' started by Red_Dragon, Feb 23, 2004.


  1. Red_Dragon

    Red_Dragon Farmall Cub

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    Can you flip an alterntor around and run it backwards? Can it be modded to work this way?

    -J
     
  2. lostneye

    lostneye Farmall Cub

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    I believe so not 100% sure but IIRC I've seen it on a late model ford to fit a supercharger install.
     
  3. Hooper

    Hooper Y-Block King

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    Flipping an alternator

    Hmmm, seems like you could not, to me.

    Lets see, electromagnet spins inside of windings, forcing electrons to travel to the negative terminal of the battery from the positive side. Wouldn't spinning the alternator the reverse direction cause the electrons to flow the opposite direction in the wires, pushing negative electrons toward the positive side of the battery? Now, if you reversed the input/output wiring, it seems like it should work, except, my alternator has vanes on it which force air through the alternator to keep it cooler. Reversing the direction of spin would negate that cooling factor substantially... seems like the alternator would overheat....
     
  4. Paul LaBar

    Paul LaBar Farmall Cub

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    I think this would work. The internal regulator converts AC (hence alternator) to DC and essentially takes the positive half of the AC sine wave and sends it to the battery and accessories. I think that sine wave will be generated no matter which way the shaft spins.

    My vote is to hook it up backwards and measure the voltage while running the truck off the battery. I bet it works just fine (otherwise there'd be clockwise and counterclockwise alternators out there to accomodate those engines that don't rotate in the same direction).

    HTH

    Paul :)
     
  5. lostneye

    lostneye Farmall Cub

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  6. Paul LaBar

    Paul LaBar Farmall Cub

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    Good point. I was more interested in whether the alternator would generate 12 volts positive, than whether it would last.

    Paul :)
     
  7. mdmcs1

    mdmcs1 Farmall Cub

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    if you use a 12si alternator fan it would cool fine, since that style fan will just pull the air through the alt in the opposite direction. the 12si fan has more of a turbine style blades so they work well in reverse too
     
  8. Red_Dragon

    Red_Dragon Farmall Cub

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    Something I forgot to mention; I inherited this truck, and my grandfather converted it from a generato to an alternator using the factory voltage regulator, so there is only one wire going to the alternator.
    Think that'll make a difference?

    -J
     

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