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Technical Fuses - where are you using them?

Discussion in 'Traditional Hot Rods' started by cederholm, Jan 2, 2020.

  1. Mimilan
    Joined: Jun 13, 2019
    Posts: 1,230

    Mimilan
    Member

    edit: Here is a 50A blocking diode
    https://www.ebay.com/itm/50A-1000V-...NEL-50-AMP-PANELS-TURBINE-STUD-A/111247550961
     
    Last edited: Jan 5, 2020
    SquintBoy likes this.
  2. used circuit breakers on the big stuff like power windows, cooling fans....
    This particular ride does not have anything like that.
     
  3. Mimilan
    Joined: Jun 13, 2019
    Posts: 1,230

    Mimilan
    Member

    So does a short on a non-fused wire.

    A normal fuse also melts, so does the filament in a blown light bulb [the weakest point "Melts"]
    50a draw on a 5a fuse will melt quickly
    A 50a draw on a 45a fuse will melt slowly

    You can buy slow blow fuses that won't blow with a temporary amp spike [these are common in Audio Amplifiers]

    Anyway :I use these style.
    You can get mini fuse blocks off some Japanese cars that these can plug into [Mazdas]
    I added a 35A fusible link between the starter and key on my 57 [ Chevy used a "total loss" system]
    download.jpg

    Edit: For the scaremongers here:
    I would rather have protection from a "Melting" fusible link than a melting wiring harness
    The Irony is: Most older cars don't have Fuse protection in the main feeds
     
    Last edited: Jan 7, 2020
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  4. acme30
    Joined: Jun 13, 2011
    Posts: 271

    acme30
    Member
    from Australia

    I am no expert on any of this but would urge that you read the above quote twice.

    In the Ron Francis wiring tips booklet they have picture of fusible links burning and strongly recommend against using them.
     
  5. Frank Carey
    Joined: Oct 15, 2009
    Posts: 574

    Frank Carey
    Member

    [QUOTE="
    In the Ron Francis wiring tips booklet they have picture of fusible links burning and strongly recommend against using them.[/QUOTE]
    I put a terminal block on top of the frame rail forward of the firewall, passenger side. Fat wire from starter to terminal block is strapped across several terminals. Fusible links are on terminal block. One end is on a strapped terminal. Other end is on a terminal wired to load. Any melting at this location is no problem. Never happened in 30 years and 77k miles.
     
  6. Boneyard51
    Joined: Dec 10, 2017
    Posts: 6,440

    Boneyard51
    Member

    While looking for “Corrosion Block”, a very, very, good corrosion preventer, on Amazon today , I saw a huge amount of different sizes and shapes of fuse and terminals blocks. Might be a good place to find one just right for any application!






    Bones
     
  7. cederholm
    Joined: May 6, 2006
    Posts: 1,748

    cederholm
    Member

    Okay, what about wire gauge size? What size would you recommend for the main power to the fuse box and then for other wires. Applications and schematic above. Remember, I'm running a stock 12v generator for the '60s. I think my biggest power draw will be the headlights, my heating fan in from a computer and draws less than an amp.

    Any advice is appreciated.
    Carl
     
  8. G-son
    Joined: Dec 19, 2012
    Posts: 1,276

    G-son
    Member
    from Sweden

    Figure out how many amps each circuit needs, select a wire size approved for that current plus a safety margin (possibly a bit larger wire to the headlights as voltage drop there hurts light output a lot), add a suitable size fuse to all circuits.
    Add total max current to the fuse box, that current tells you the minimum feeder wire size to the box.

    Sorry, can't help you with the data about what wire size can handle what current. I can handle most types of measurements, but AWG wire sizes are just backwards for no apparent reason and I rarely come across them here in the civilized part of the world so no reason for me to get a good grip about that madness. ;)
     
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  9. Carl, I run an 8ga on mine . Overkill? perhaps. Of the opinion that size matters and larger is better. Remember, you are protecting the wire.

    Ben
     
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  10. Boneyard51
    Joined: Dec 10, 2017
    Posts: 6,440

    Boneyard51
    Member

    Nothing anywhere in a car smaller than 14 gauge. If you are not sure about a wire size... go to the next size larger. A few dollars here, can save trouble down the road. OEMs get away with small wire, but I wouldn’t try in on a build.




    Bones
     
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  11. 49StreetRod
    Joined: Apr 10, 2019
    Posts: 45

    49StreetRod
    Member
    from Irwin, PA

    I ran 12g on everything. 10 on the main wire to my fuse panel I made in the glove box. Like boneyard said, if unsure go next size. Not going to hurt anything. I also ran relays to all my switches. I am basic though as far as options-push button start, turn signals, radiator fan, lights, horn.

    My first time wiring and just reading and watching some videos I learned a lot.

    I did make a fuse box with enough space to add things as I do more to the project. I can post a picture later.
     
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  12. Ziggster
    Joined: Aug 27, 2018
    Posts: 1,697

    Ziggster
    Member

    I really wouldn't use one either, but Toyota/Lexus used them on their Land Cruisers/LX's. They were used on the main power feeds to the fuse boxes. I think my 97 LX450 has three of them. These vehicles cost US$50K back then, and I'm sure Toyota/Lexus wasn't skimping on cost for a reason to use them.
     
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  13. Boneyard51
    Joined: Dec 10, 2017
    Posts: 6,440

    Boneyard51
    Member

    I never liked fuse able links, because they were a pain in the ass to replace. I wouldn’t use them now for the same reason. If you need high amp protection use a maxi fuse or heavy circuit breakers.
    I used to out fit high amp systems and would protect them with 350 to 500 amp fuses.






    Bones
     
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  14. I wired my 40 Ford truck with no fuses drove it 10 or 12 years with no problems.
     
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  15. G-son
    Joined: Dec 19, 2012
    Posts: 1,276

    G-son
    Member
    from Sweden

    For sure, the fuses are completely useless most of the time, just an extra expense. But that one time when there IS a problem they are the difference between a blown fuse and, say, a burning car, the garage it sits in, the other twelve cars in there, the house next to it and the rest of California that hasn't already burned.

    And... I wonder what the insurance company says when they figure out the cause was not having any fuses.
     
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  16. Ziggster
    Joined: Aug 27, 2018
    Posts: 1,697

    Ziggster
    Member

    Yep. I had a coworker whose car (modern daily driver) was destroyed by fire. When it happened the car was fortunately outside in his driveway, but was usually kept in his garage. Luckily his house didn't catch fire.
    The cause was a frayed wire that was part of a wire bundle that passed through the firewall. I can't remember exactly, but I think the grommet had not been installed at all or was improperly installed. In any event, it is absolutely necessary to provide fuses for instances just like this. Don't forget that vermin like to nest in and chew on wires when vehicles are parked for some time. I'm sure we all have stories of mice, squirrels, etc. that have set up residence in our vehicles.
     
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  17. birdman1
    Joined: Dec 6, 2012
    Posts: 1,591

    birdman1
    Member

    Disable link at the starter solenoid for the alternator like Ford
     
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  18. phoneman
    Joined: Dec 5, 2010
    Posts: 109

    phoneman
    Member
    from Missouri

    Fusible links are to protect the wire. They are wire with a jacket that does not burn. As a rule of thumb fusible links are 2 gauges smaller than the wire they are protecting. Example if protecting 12 gauge wire use a 14 gauge fusible link. I think all newer cars use Maxi fuses instead of fusible links.
     
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  19. Boneyard51
    Joined: Dec 10, 2017
    Posts: 6,440

    Boneyard51
    Member

    The fusible link on most later cars was for all the feed going to the fuseblock. It has to be big enough to carry all circuits. If used it could let a smaller wire get red hot and melt before the fuseable link blew, if there were no fuses on the individual circuits.






    Bones
     

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