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GM alternator one wire conversion?

Discussion in 'The Hokey Ass Message Board' started by deluxester, Feb 28, 2009.

  1. deluxester
    Joined: Mar 14, 2004
    Posts: 474


    I remember years ago I had run a conventional gm alternator as a one wire type by connecting a jumper between the batt terminal and one of the two tabs at the top of the alternator. Does anyone know which tab is the correct one to use?
  2. flip7262
    Joined: Sep 26, 2003
    Posts: 128

    from Minnesota

    Should be the one on the left side when facing the front of the alt.

  3. budd
    Joined: Oct 31, 2006
    Posts: 3,478


    terminal #2, the red arrow.

    Attached Files:

    • ALTj.JPG
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  4. v8 Bake
    Joined: Dec 23, 2007
    Posts: 296

    v8 Bake

    if you replace the internal regulator with a self exciting one all you need is the big power wire.

  5. Desert1957
    Joined: Aug 15, 2007
    Posts: 50

    from Pa/Md

  6. why not just use a one wire alt. and convert your cars electrical system? Wouldn't that be easier then trying to jerry-rig a one wire system? can you say "HACK"?
  7. FalconMan
    Joined: Sep 9, 2008
    Posts: 1,354

    from Minnesota

    I have done it both ways. The 3 wire is much better if you ever need to replace it on the road. They are available cheap everywhere. A one wire..... you are screwed into buying a 3 wire and then jerry-rigging in the parts store parking lot.

  8. Not if you just break down and spend the money for the right parts. How much more does a one wire alt. cost? You can't carry a spare? This is why I carry Auto Club. To get me home safely or to a repair shop. Shit just happens. It all depends on how you deal with it. What's the potentail of making things worse by hacking it? Or burning it to the ground? Bring Marshmallows, we'll have a bonfire.
  9. deluxester
    Joined: Mar 14, 2004
    Posts: 474


  10. d2_willys
    Joined: Sep 8, 2007
    Posts: 4,165

    from Kansas

    One wire units are ok if 1) you like revving your engine up when it starts just get the alternator excited, 2) if you like having the voltage regulator monitor the voltage right at the alternator and not at the battery. You could have a not so good wire from the battery to the main alternator terminal and when you have big loads on the battery it will undercharge, because the sensing is done at the alternator. I prefer the 3 wire units.
  11. How hard is it to do it the right way and route a sensing wire to your positive junction block? Certainly cheaper than lugging around a spare one-wire alternator and cleaner than jerry-rigging a three-wire in the parking lot.

    All you need to do is run one extra little wire. A monkey could friggin' do it.
  12. flynbrian48
    Joined: Mar 10, 2008
    Posts: 7,169


    What? I just went to a NAPA store here and bought a one wire, 55 amp off the shelf, it's a stock item for conversions, even listed as "conversion alternator", in EVERY NAPA store. And what's with a spare? I've NEVER had an alternator fail on the road in 40 years driving.
  13. 49 lincoln
    Joined: Feb 28, 2006
    Posts: 251

    49 lincoln
    from reno

    I had a one wire, but it didn't give me enough juice when I had lots of things going, so I converted it with a 3 wire internal voltage regulator and wired it ala Mad Electrical. Now it senses from a distribution block and keeps me supplied with plenty!
  14. farleydog
    Joined: Mar 2, 2009
    Posts: 4


    used to build the one wire, all it is is a mid 70s and up se 10 or se 12 delco unit (se) standing for self energizing. it has a feild terminal which can be connected straight to batt term basically all your doing is bypassing the ignition switch. down side is if you dont start car for weeks at a time it can drain battery. but works great for a daily driver. to be sure you have an (se) unit make sure it takes the flat 2 wire plug not the square type like used in the 60s.
  15. True, if your just keep your shit in good working order you won't need a spare, or a hack-conversion. I too have never had an alt. go out on me at any time. Or a starter, or a carb. Water Pump? Yes. But like I said before, this is why I carry AAA. Just in case.
  16. adc
    Joined: Jan 23, 2008
    Posts: 4


    Any chance you could tell me what the part number(s) were...?

    The counter persons (high school help) at my local NAPA are often "challenged" when it comes to finding parts that everyone else easily locates.
  17. 53sled
    Joined: Jul 5, 2005
    Posts: 5,818

    from KCMO

    3 wires are superior to 1. Learn to read a diagram.
  18. yellow wagon
    Joined: Jun 13, 2007
    Posts: 612

    yellow wagon
    from WI

  19. Bob Dobolina
    Joined: Jul 27, 2006
    Posts: 332

    Bob Dobolina

  20. Deyomatic
    Joined: Apr 17, 2002
    Posts: 3,095

    from CT

    The alternator that Budd pictured above is the three wire type, right?
  21. wildearp
    Joined: Oct 24, 2007
    Posts: 522

    from tucson, az

    I have wired several cars and have tried two different one-wire style alternators. IN both cases they would shut off at idle and produce low voltage at low rpm. It really doesn't take much more work to just hook up the other two wires as intended. People obsess about the 1 wire because their car is "so much cleaner", yet have so many other things wrong with it that the one wire offers no aesthetic improvement.

    A couple friends insisted their 1 wire alternators were the best thing since sliced bread, yet their batteries would keep going dead. ONe complained their stereo was full of static and cutting out. Stereos don't like to run on 8 volts...............

    Go with your one wire and defy the experts!!!!!!!!!!!
    Last edited: Jun 9, 2009

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