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Fusible link in alternator charge wire

Discussion in 'The Garage' started by rcamacho, Feb 13, 2005.

  1. rcamacho

    rcamacho 1/2 ton status

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    I'm running a 120A 17si alternator with my electrical system laid out like the MADD new system:

    http://www.madelectrical.com/newstuff/

    The junction block on the firewall is the alternator sense point. However, I need to upgrade the alternator charge wire from 8ga to 4 ga in order to handle the additional amperage. I also run a winch off of a single battery installation for now so I'm considering upgrading the battery charge wire from 10ga to 4ga in order for the alternator to provide some meaningful amperage during winching. Else, the 10ga will have too much voltage drop and potentially blow the fusible link.

    Q: anyone out there running 8 ga fusible links on an otherwise 4ga wire line or is this a waste? It seems to me like the fusible link would introduce voltage drop which is the whole point of upgrading the line to begin with.
     
  2. dontoe

    dontoe 3/4 ton status GMOTM Winner

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    I rerouted the stock wiring to the starter for a remote solenoid and also a isolator for my aux battery.
    Point is I replaced the fusible link with a 40 amp Circuit Breaker. 30 kept reseting when A/C and lights and all the "high load" stuff was on at the same time. Exciting driving at night!
    Never had a problem outa the 40 amp though. This is the wire that powers the stock fuse panel for the truck.
    Probably need something on the 1 gauge going bumper to bumper but I heard the winch or jumper cables hooked to another vehicle draws something like 500 amps under severe load. I double insulated it though.
     
  3. rcamacho

    rcamacho 1/2 ton status

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    Well I've terminated a custom length 4ga wire from the alternator directly to the firewall junction block without a fusible link. The junction block to terminal block still has a fusible link for protection. This has eliminated all voltage drop from the alt to the terminal block.

    Next I'll be adding a 4ga link directly from the alt to the battery and eliminating the 10 ga battery link to the junction block. Essentially I'll have a 4ga buss from the battery through the alternator terminal to the junction block. I'm taking the alternator sense wire to the junction block to accomodate any voltage drop over the 7ft 4ga.

    The only risk I see here is perhaps grounding out the 4ga on the engine over the 7ft run but the insulation is very thick and I'm running convolute tubing around it.
     

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