On the road again....almost!

Discussion in '1947-1954' started by mobileortho, Jan 7, 2014.

  1. mobileortho

    mobileortho Member

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    Whew!! Finally got the replacement engine in but I've run into a problem with the alternator, it won't turn off. I had that issue before and traced the problem back to the ignition wire being disconnected. No issues with that wire now but it only shuts off if I disconnect the battery. Can't figure it out this time. Any thoughts?
     
  2. Bill Hanlon

    Bill Hanlon Member

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    You need a diode to prevent self energizing while running. Where to install it depends on what kind of alternator & voltage regulator you have.
     
  3. mobileortho

    mobileortho Member

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    Thanks Bill!
     
  4. mobileortho

    mobileortho Member

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    Haven't got around to getting the diode yet, but I'm wondering if the internals may be skewed. Shouldn't it turn off if you unplug the pigtail??
     
  5. vwnate1

    vwnate1 Member

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    Yes , that should kill it .
     
  6. mobileortho

    mobileortho Member

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    That's what I thought, but mine still runs. Any ideas?
     
  7. mobileortho

    mobileortho Member

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    I'm good. Got an online coupon for $50 off @ Advance Auto so I just bought a new one, problem solved.
     
  8. vwnate1

    vwnate1 Member

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    Run On

    Yes ;

    Clearly the alternator has nothing to do with your run on problem .

    Time to have fun (?) finding the back feeding circuit .

    -Nate

     
  9. mobileortho

    mobileortho Member

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    The old one was bad, I had it tested before I bought the new one and as I suspected, the rectifier? failed.

    By the way Nate, how you feeling?
     
  10. Bilbo

    Bilbo Member

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    Yeah, if an internal diode fails, as a shorted diode, it will backfeed internally and keep the alt. energized. Most often its the diode trio on the output of the alt. Anyway, problem is solved. BTW, those alternators are easy to repair when it's just a diode problem. Disassemble, separate the diode leads, and test each with forward bias and reverse bias. They should only pass voltage in one direction... period. Find the faulty one(s) and replace.
     
  11. vwnate1

    vwnate1 Member

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    Fixed !

    Yay ! you fixed it .

    I don't see how it made the engine run with the wires disconnected though...:confused:

    I feel.....better .

    Certainly much better than I felt before the operation but neck pain persists as the bones and screws in my vertibrae knit .

    The worst part is not being able to work , drive or RIDE MY MOTOCYCLE ~ this is torture .

    I simply cannot rush things else it might not heal up correctly .

    -Nate

     

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