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How do I wire this to my alternator?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by divorced, Nov 4, 2004.

  1. divorced

    divorced 3/4 ton status

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    I bought this a long time ago and forgot how to wire it. Do I just connect the ring terminal to the post on the back of the alternator and then run a wire from there to the batteries?

    [​IMG]
     
  2. mrk5

    mrk5 The Sticker Guy Moderator Vendor GMOTM Winner Author

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    That's how mine is hooked up. I don't have a plug, but the wire runs from the post on the alternator over to the battery.

    I had a 6.2 with dual alternators, so when I swapped in the 350 I had to do new wires for the alternator.
     
  3. btolenti

    btolenti 1/2 ton status

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    [ QUOTE ]
    I bought this a long time ago and forgot how to wire it. Do I just connect the ring terminal to the post on the back of the alternator and then run a wire from there to the batteries?

    [​IMG]

    [/ QUOTE ]

    Yes you are correct. plug the harness into the alternator, attach the red wire with the ring terminal onto the post at the rear of the alternator, then run a large 8 or 10 gauge wire from the alternator post to the battery.
     
  4. divorced

    divorced 3/4 ton status

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    Sounds easy enough, thanks guys.
     
  5. cegusman

    cegusman 3/4 ton status

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    Where did you get the plug from?
     
  6. 85mudblazin

    85mudblazin 1/2 ton status

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    This may sound stupid but what is that??
     
  7. sickquad

    sickquad 1/2 ton status

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    I second the stupid question, what is that?
     
  8. lukebaby1

    lukebaby1 1/2 ton status

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    I believe it is a jumper setup for a one wire alternator hook up. /forums/images/graemlins/thinking.gif
     
  9. btolenti

    btolenti 1/2 ton status

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    [ QUOTE ]
    I believe it is a jumper setup for a one wire alternator hook up. /forums/images/graemlins/thinking.gif

    [/ QUOTE ]

    That is correct. That red wire is effectively a jumper to provide 12 volts to effectively "start" the alternator.
     
  10. sickquad

    sickquad 1/2 ton status

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    Wow, that sounds interesting, but I don't get it. Doesn't an alternator always charge when it is spinning?
     
  11. Muddytazz

    Muddytazz 1 ton status

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    [ QUOTE ]
    Wow, that sounds interesting, but I don't get it. Doesn't an alternator always charge when it is spinning?

    [/ QUOTE ]
    It will only charge if its hooked up to the battery
     
  12. mrk5

    mrk5 The Sticker Guy Moderator Vendor GMOTM Winner Author

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    You can kinda think of the alternator like a pump. If line pressure is the same as pump output pressure the fluid doesn't go anywhere. If line pressure drops below pump pressure, the pump starts putting out fluid. With the alternator the voltage is pressure and current is the fluid.

    Does that help?
     
  13. sickquad

    sickquad 1/2 ton status

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    [ QUOTE ]
    [ QUOTE ]
    I believe it is a jumper setup for a one wire alternator hook up. /forums/images/graemlins/thinking.gif

    [/ QUOTE ]

    That is correct. That red wire is effectively a jumper to provide 12 volts to effectively "start" the alternator.

    [/ QUOTE ]

    I don't understand the "start" the alternator thing. Does the circuit turn on the alternator in some way when it needs current?
     
  14. btolenti

    btolenti 1/2 ton status

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    the 12Volts to that connector provides voltage to the "field" of the alternator. The spinning alternator rotor in this magnetic field, is what causes the generation effect of the alternator. If you do not hook this 12 volts to the "field" of the alternator, all you would have is a spinning hunk of iron...

    The one wire aftermarket alternators have this built into the alternator, but most require a certain speed to "start" the alternator. Most see this when they have to rev the engine right after startup to see the alternator kick on. (ie right after startup a voltmeter will read just 12 or so volts - essentially battery power....when you rev the motor and bring the alternator up to proper speed, it will start generating, and your voltmeter should read 13-14 volts.)

    Not sure if I am gettting the point across... /forums/images/graemlins/dunno.gif
     
  15. walla2k5

    walla2k5 1/2 ton status

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    Right on the nose....exciter wire... /forums/images/graemlins/waytogo.gif /forums/images/graemlins/usaflag.gif
     
  16. sickquad

    sickquad 1/2 ton status

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    I get it, good explanation. Learn something new everyday.

    -Chris
     
  17. divorced

    divorced 3/4 ton status

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    [ QUOTE ]
    Where did you get the plug from?

    [/ QUOTE ]


    I got mine from the local Napa store. I think it was around $12 or $15. I bought it to make it easy to wire the alternator in a vehicle that had no wiring, but have since scapped the vehicle. I guess I will use it on my K-20 to get rid of some extra wires. They also work good for wiring demolition derby cars.
     

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