7.3 idi alternator swap

Discussion in '6.9L IH & 7.3L IDI Diesels' started by BlueHound, Nov 13, 2017.

  1. BlueHound

    BlueHound Registered User

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    Hey everyone I have a 1991 F250 7.3 idi and the charging system has been nothing but trouble since day one. I want to swap it to an internally regulated 3g alternator. I just need to know what alternator to buy and what I need to change/splice to make it work.
     
  2. tradergem

    tradergem Full Access Member

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    A 7756-3N-2G 130 amp alternator is supposed to work. I will find out Wednesday when I install the new one I just bought to replace my old 100 amp 1G alternator and external regulator. This model comes with the dual v-belt pulley which is what I needed for my 1990.

    James
     
  3. Runningaford

    Runningaford Full Access Member

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    I just switched over to a single wire alt. I'm very pleased so far.
     
  4. Macrobb

    Macrobb Full Access Member

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    I like the 3g style more than a '1-wire', because you have a feedback/sense wire. It's an extra wire to install, but it means that the alternator can compensate for voltage drop, either due to wire thickness or just plain load.
    It also allows you to run a (diode)'battery isolator' setup if you want, for a second set of batteries.
    A 1-wire can't handle the voltage drop of such a device, a 3g works just fine if properly wired.
     
    icanfixall and Thewespaul like this.
  5. Grady J

    Grady J Registered User

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  6. raydav

    raydav Full Access Member

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    I have been converting all my old stuff to 3G. They can have either one or two wire regulators. With two wire you can have an "idiot light". And if you get them from eBay the seller might not know the difference.
     
  7. whiteboyslo

    whiteboyslo FNG

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    Yes, it works. I have that one in my 91.

    Mike
     

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