Flame-broiled mouse

Discussion in 'Troubleshooting & Diagnosis' started by Tphil413, Apr 16, 2008.

  1. Tphil413

    Tphil413 Veteran Member

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    Jun 1, 2007
    San Francisco, CA
    Sorry, not sure what the fuseable link is. Is this the wire lead that attaches to the starter selenoid and feeds all the other wires up on the firewall? The wire that looks toasty is attached to that lead appears to attach to several other wires that connect to a block with three connections attached to the firewall behind the dizzy. The melted spot is where I have this lead going in and multiple wires coming out. Everything north of that spot looks untouched. Do you think I can I avoid a full engine harness replacement?
     
  2. K5JMP

    K5JMP Veteran Member Lifetime Gold Member

    yes... and yes;) a fuseable link is a piece of a special type wire that melts and burns away at a set amperage. just like a fuse would do

    you will need the appropriate chunks of fuseable link wire and primary wire, crimp-type butt splice connectors (remove the crappy hard plastic insulation) for mechanical strength, soldering iron and heat-shrink tubing... open the harness loom and see how far back you need to go to get to virgin wire. measure from there.

    easiest way to get them is a pick-a-part.... or PM F-Body Mike or Pete at F-Body Warehouse. I'd bet they can get you squared-away:)
     
  3. Tphil413

    Tphil413 Veteran Member

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    Jun 1, 2007
    San Francisco, CA
    What I don't understand is how the starter, blower, lights, tach, etc. are still working while the ignition components and accessories (radio, wipers, etc.) are not. Don't these all connect via the same fusible link? Could my problems be further up the harness not at the fusible link?
     
  4. Tphil413

    Tphil413 Veteran Member

    219
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    Jun 1, 2007
    San Francisco, CA
    Any ideas...anyone? I have a 3000 lb. paper weight in my garage. I could really use some good advice here. I will buy the engine harness if need be, but I'd rather save the $140 if I can. Does the fusible link theory sound reasonable? Can anyon explain how the working components are wired? Are they fed via another power source or are they all linked to the same fusible link on the solenoid?:confused:
     
  5. EricsZ28

    EricsZ28 Veteran Member Lifetime Gold Member

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    Feb 28, 2006
    Here and there...
    They are all fed from the same source. Replace the fusible link & go from there.

    Keep in mind that toasted wires may still pass some current - just not enough to operate your electronics due to the resistance imposed by the charred wires. You really need to replace the bad wire & go from there.

    You may be able to find fusible link wire at your local parts store (get 2 sizes smaller than the main wire). While you are at, check your grounds.

    Which see-through fuel filter were you running? One of those glass ones or something like the Fram plastic filters?
     
  6. EricsZ28

    EricsZ28 Veteran Member Lifetime Gold Member

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    Feb 28, 2006
    Here and there...
    Wait, this is a '71 - this is different than my '80. I believe my comments are still correct. Follow this wiring diagram & start probing with a test light if the fusible link doesn't solve the problem [​IMG]
     
    Last edited: May 21, 2008
  7. Tphil413

    Tphil413 Veteran Member

    219
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    Jun 1, 2007
    San Francisco, CA
    It's a glass one like this...
     

    Attached Files:

  8. Tphil413

    Tphil413 Veteran Member

    219
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    Jun 1, 2007
    San Francisco, CA
    Big Mouse,

    I only see one fusible link in the diagram, between the battery and the junction block. Shouldn't there be one between the solenoid and coil? If not wouldn't I have spark at the plug? :confused:
     
  9. EricsZ28

    EricsZ28 Veteran Member Lifetime Gold Member

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    Feb 28, 2006
    Here and there...
    No. The fusible link simply acts like a fuse between the 12V+ from the battery & the fuse box. I'm not entirely sure on what I'm about to say (I'm sure somebody will correct me if I'm wrong) - but I believe the wire between the starter solenoid & the coil energizes the coil upon starting & then the other wire (20 w/or/ppl) energizes the coil after the starter is disengaged. Either way - you don't need a fusible link on those wires. One (or both) of those wires may be resistor wires, but again, I'm not sure on that.

    I'm more concerned that you figure out WHY the fusible link blew in the first place. Did the fire melt some insulation & cause a short to ground on either the wire labeled 10 R or 14 B?

    I would cut the old fusible link & then check for continuity to ground on both of those wires before you replace the fusbile link. If that checks out (obviously you don't want continuity from those wires to ground) , I would think you would be OK to replace the fusible link & check for power to your accessories.
     
  10. K5JMP

    K5JMP Veteran Member Lifetime Gold Member

    exactly correct in all 3 instances...
    don't even have to cut into the FL... just test from the ring-lug on the end...
     

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