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Thread: Atomic EFI, adding an in-tank fuel pump.

  1. #1

    Default Atomic EFI, adding an in-tank fuel pump.

    I currently have an Atomic EFI in my '72 Cutlass and want to install the 12-303 fuel pump. Is there a wiring diagram out there anywhere that shows the connections for these? Atomic says no relay needed, new pump says relay is required. I tried calling tech support, but they are “unexpectedly closed” today? Any input is greatly appreciated.

  2. #2


    The Atomic EFI fuel pump driver supports 20 amps of current without the need for a relay. So connect the Atomic orange wire to the fuel pump gray wire, the purple wire connects to the fuel gauge, and the ground wires connect to the chassis or battery negative post.

  3. #3


    Thanks for the information! I finally got in touch with tech support and they said the same thing. I installed it yesterday and it’s working great. Thanks again.

  4. #4


    You're welcome.

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