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New alternator wiring question

Discussion in 'Retro-Fit & Aftermarket Accessories' started by Mobius, Nov 12, 2019.

  1. Mobius

    Mobius Full Access Member

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    Eric
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    Engine Size:
    350 SBC
    I recently installed a CS144, 140 amp alternator, to power my dual electric cooling fans and whatever else I add down the road. I’ve read through some of the info here, and know I need to upgrade some of my wiring. People talk about the charge wire. Are you just adding a bigger wire from the alt to the firewall junction block? Are you running a wire directly from the alt to the battery positive post? What else beyond this and the grounds needs an upgrade?
     
  2. 75gmck25

    75gmck25 Full Access Member

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    5.7
    I found it easier to run the new wire directly over from the alternator BAT terminal to a junction block inside the passenger side fender, and then to the battery positive. I pulled a charge wire (8 gauge?) off a newer GMT400 pickup and it already had the fusible link molded into the wire.

    I pulled the junction block inside the fender off the firewall of another squarebody, and also used it to connect a fused relay for my upgraded headlight wiring.

    Bruce
     
  3. Matt69olds

    Matt69olds Full Access Member

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    If the charge wire is bigger than whatever goes from the junction block to the battery, that needs to be upgraded as well. Otherwise, the bigger wire will stay cool, the smaller wire will get hot and eventually let all the smoke out of the wires. Anyone who know anything about automotive electrical systems knows it’s the smoke that makes things work.
     
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  4. Mobius

    Mobius Full Access Member

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    I definitely don’t want to let all the magic smoke out. Thanks for the advice, gentlemen.
     
  5. jjester6000

    jjester6000 Full Access Member

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  6. C10MixMaster

    C10MixMaster Full Access Member

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    F3B7CC4E-75E7-4820-B39C-39161883F17E.jpeg
     
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  7. MikeB

    MikeB Full Access Member

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    When I re-wired my 82, I used 8 gauge from ALT to a new junction block on the firewall above the starter. From there I ran 8 gauge to BAT terminal on starter, and another 8 gauge wire to the fuse panel.

    On another note, I suggest using cross-linked polyethylene insulated wired that is SXL or GXL rated, not the wire you find at hardware and auto parts stores. Here's a really good value: https://www.jegs.com/i/JEGS/555/10841/10002/-1

    Good article: https://www.purkeys.net/are-you-buying-the-right-wire/
     

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