3g -130amp 4awg Fuse Size?

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


  1. Grabbin' Asphalt

    Grabbin' Asphalt Advanced Member

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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??
  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.


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  3. Grabbin' Asphalt

    Grabbin' Asphalt Advanced Member

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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.
  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.
  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.
    Grabbin' Asphalt likes this.
  6. Grabbin' Asphalt

    Grabbin' Asphalt Advanced Member

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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:
  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...

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