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Thread: MEFI 3 Question

  1. #1
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    MEFI 3 Question

    I have the upper half of a marine harness and a Mefi 3 ecm that I am trying to work with, but having issues. If I power the red connector to the battery and the grounds to the ground of the battery, shouldn't I be able to see the ecm, or do I need the lower half of the marine harness? The half I have goes to the injectors, ecm and solenoids.

    Thanks

  2. #2
    Fuel Injected! roughneck427's Avatar
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    See it?? as in hook a scanner up to it or try and flash it?

  3. #3
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    Quote Originally Posted by roughneck427 View Post
    See it?? as in hook a scanner up to it or try and flash it?
    Can't do either

  4. #4
    Fuel Injected! roughneck427's Avatar
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    What cable are you using? Look in the other mefi thread one of the guys posted the read and write wire pin out is there

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    Quote Originally Posted by roughneck427 View Post
    What cable are you using? Look in the other mefi thread one of the guys posted the read and write wire pin out is there
    AKM cable and I get power at J2, pin 1. That is why I thought that I should be able to get something from the ECM.

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    Fuel Injected! roughneck427's Avatar
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    well I used datamaster mefi 3 just fine with my LT1 cable all I needed was ground and serial going to my aldl cable

  7. #7
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    Quote Originally Posted by roughneck427 View Post
    well I used datamaster mefi 3 just fine with my LT1 cable all I needed was ground and serial going to my aldl cable
    So you just powered and grounded the pins and hooked up the cable without going through a harness of any type?

  8. #8
    Fuel Injected! roughneck427's Avatar
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    power and ground your harness key on power also. connect the ground that would go into the LT1 aldl to the Mefi 10 pin dlc ground and connect the serial data the same way
    Attached Images Attached Images

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    So it looks like I will need to have a way to key it on and off. I do not have a harness that does that. Just the upper efi harness and no way to key it on or off. Thanks for your help. I will need to build a harness and adapter.

  10. #10
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    Quote Originally Posted by 800xcr View Post
    So it looks like I will need to have a way to key it on and off. I do not have a harness that does that. Just the upper efi harness and no way to key it on or off. Thanks for your help. I will need to build a harness and adapter.
    Just need to get power through the upper harness to J-32. Thanks Chris!

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