3g -130amp 4awg Fuse Size?

Discussion in 'Fox 5.0 Mustang Tech' started by Grabbin' Asphalt, Aug 1, 2013.


  1. Grabbin' Asphalt

    Grabbin' Asphalt Mustang Master

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    So if a 4awg wire can only handle around 136amps before it burns. Should the relative size fuse be 125amps or 150amps??

    Why do I see kits that have 200amp fuses?? The fuse wouldn't blow before the wire's toast, correct??
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  2. jrichker

    jrichker StangNet's favorite TOOL SN Certified Technician Founding Member

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    I would recommend 125 amps. The fuses all have the capability of carrying up to 110% of load for an extended period of time.
    #2
  3. Grabbin' Asphalt

    Grabbin' Asphalt Mustang Master

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    Ok thanks for confirming that for me, I trust your "Intel".
    I'm doing the 3g upgrade tomorrow, so I wanted to cover all the fine points.

    Got a barely used Ford Motorcraft 3g 130amp, top bolt hole already tapped, already has right pulley, 4awg power wire already assembled with mega fuse holder with 200amp fuse(which I will change to 125amp) for $150. Came off an '87 mustang.

    Already ran my 4awg grounds, neg battery pigtale and rear firewall/intake.
    #3
  4. mikestang63

    mikestang63 Mustang Master

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    All you need to do is wire up the stator wire and clearance the alt bracket. Run the 3G power cable to the Battery side of the solenoid.
    #4
  5. Shakerhood

    Shakerhood Well-Known Member

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    I used the 125 Amp Fuse in my car too, I have always been confused by peoples choices of larger fuses also.
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  6. Grabbin' Asphalt

    Grabbin' Asphalt Mustang Master

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    I've heard that some people didn't have to cut the alternator bracket while most have to cut it,
    I'm crossing my fingers for that :chin
    but I won't cut/splice that stator wire until I've got it mock installed.
    I've been running a 175 black magic fan with crank/waterpump underdrive pulleys.
    While using the stock alternator 75amp and stock pulley.
    I'm soooooooo ready for some JUICE!!!:flame:
    #6
  7. jrichker

    jrichker StangNet's favorite TOOL SN Certified Technician Founding Member

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    Modifying the alternator mount bracket isn't t that big of a deal. I used a rotary file in an air drill and had it all filed out and smoothed in about 10 minutes. I removed more than the minimum amount of metal and smoothed it out so that it looked like a factory job after a few thousand miles of dirt got on it...
    #7

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