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M1009 alt's

Discussion in '1982-Present GM Diesel' started by bear76, Oct 5, 2006.

  1. bear76

    bear76 1/2 ton status

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    I've gotten confused about the m1009 alt set up and have a few questions:

    1) Are both alt's floating ground? Or is the passenger side the only one?
    2) Can any GM alt replace either alt?
    3) When converting to 12v, can you use either alt (floating ground or not)?
    4) When converting what dose "removing the ground from the system" mean? (quoted from the official 12 volt convert. instructions that someone will direct me to, I've read it 20 times).
    5) I assume from reading said instructions that all you need to do is ground the single alt to the block and now its not floating, right?

    Please help
    Thanks.
     
  2. Smitty

    Smitty 1/2 ton status

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    1. Both of the alternator's are the same (floating ground)from the factory. However, the left alternator is grounded to the block from the factory.
    2. Not sure about this. I believe you can.
    3. I used the alternator on the right side. I kept the left alternator as a spare.
    4. I removed the ground wire from the left alternator and used it on the right alternator.
    5. Correct
     
  3. bear76

    bear76 1/2 ton status

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    Thanks Smitty,

    If going 12 volt can I use a any high amp GM alt that fits on the passenger side? I assume that once I go 12v it would work the same as any other car, grounding wise.
    I don't know why I can't wrap my brain around this 12/24 system. I guess I'm just so biasd toward 12v.

    Thanks.
     
  4. Smitty

    Smitty 1/2 ton status

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    I guess you could. You just wouldn't need to run the external ground wire since the different alternator would have an internal ground. Remember that those original alternators are 100 amp and if you still have them, they're free. I stuck with the one alternator and dual batteries. The only reason that they had the 24 volt system was for the NATO jump start capability and the starter. I dropped in a 12 volt gear reduction starter and I'm very happy with the results.
     

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