Fuse taps using the hot side aka wrong side

Discussion in 'Power Magic Pro' started by Pbets, Jan 17, 2016.

  1. Rajagra

    Rajagra Well-Known Member

    Messages:
    2,429
    Likes Received:
    1,808
    Country:
    United Kingdom
    Dash Cam:
    Mini0806
    Nigel's image is correct. Due to it being an accurate schematic, nothing to do with the colouring. :cool:
    The only thing you could dispute is the wording. "Correct" vs "wrong" way round might be more objectively worded safer/less safe. They are different, the less safe version might even have an application if you check the wire rating.
    But the safer version is more proper, and should be the default choice unless you have a valid reason to go the other way.
     
  2. Ralph2

    Ralph2 Active Member

    Messages:
    610
    Likes Received:
    165
    Location:
    Edmonton AB
    Country:
    Canada
    Dash Cam:
    BlackVue 650GW in 2011 Highlander
    What this forum needs is a "beating a dead horse" smiley. But.. I still beg to differ with your interpretation of correct. The "add a fuse" is used because there is not an available slot. But.. consider the wiring if there was. From the hot side.. through the fuse.. to the application. That.. is how every fuse in the fuse panel works. In fact the whole fuse panel is an application of "add a fuse" as there is a circuit breaker (or fuse) feeding it.
    If.. you want to mimic the way the engineers designed it you will place the new add a fuse one way, source from the main buss.. through the fuse.. and to the application. "Your" way takes the source "through" the original fuse.
     
    CDNinHH likes this.
  3. Rajagra

    Rajagra Well-Known Member

    Messages:
    2,429
    Likes Received:
    1,808
    Country:
    United Kingdom
    Dash Cam:
    Mini0806
    If the fuse box is fed by a single, monster cable - and it may well be - then that would eliminate the potential problem. Provided there were no weak links inside the fuse box (thinner wires, circuit board traces, or whatever. Or even the fuse sockets themselves.)

    Edit> Another thought - anything that goes through a relay, like switched accessory power, must not exceed the relay's capability. Adding any circuit that isn't fed through existing fuses could do so.
     
    Last edited: Feb 6, 2016
  4. Nigel

    Nigel Well-Known Member

    Messages:
    5,322
    Likes Received:
    2,296
    Location:
    Devon
    Country:
    United Kingdom
    Dash Cam:
    Gitup Git3, Mini 0806
    I think you are assuming that all the fuses in the fuse panel are supplied by a single high current bus in the same way that a house fuse box is. However that is often not the case in an automotive fuse panel, the fuses are often (I think normally) supplied by individual wires which are only rated to match the fuse.
     
  5. jokiin

    jokiin Well-Known Member Manufacturer

    Messages:
    36,101
    Likes Received:
    18,181
    Location:
    Shenzhen, China - Sydney, Australia
    Country:
    China
    Dash Cam:
    Too many ¯\_(ツ)_/¯
    National Lampoon's Christmas Vacation
     
  6. Ralph2

    Ralph2 Active Member

    Messages:
    610
    Likes Received:
    165
    Location:
    Edmonton AB
    Country:
    Canada
    Dash Cam:
    BlackVue 650GW in 2011 Highlander
    The hot side of the fuse box is divided into segments. (all the fuse boxes, in and outside the car) Each segment is fed by relays/ circuit breakers that close (turn on) as required, thus there is a bank that turns on with the key, on with the key in ACC, a bank that turns on with the key in the starter position, a bank that is turned on all the time...........
     
  7. Nigel

    Nigel Well-Known Member

    Messages:
    5,322
    Likes Received:
    2,296
    Location:
    Devon
    Country:
    United Kingdom
    Dash Cam:
    Gitup Git3, Mini 0806
    If that is the case then you really don't know what the system is capable of supplying to each fuse, a 10A fuse may be supplied by a 10A relay and when you pull 15A through it the relay will burn out. In my car some of those relays, such as the door lock motors and window motors are soldered on the same circuit board as the security and alarm system and when they burn out (which does happen) you are in a bit of expensive trouble!
     
  8. Ralph2

    Ralph2 Active Member

    Messages:
    610
    Likes Received:
    165
    Location:
    Edmonton AB
    Country:
    Canada
    Dash Cam:
    BlackVue 650GW in 2011 Highlander
    I suspect the engineers that design the assembly take into account the total load on each segment. And.. yes you could overload an individual segment... with expensive consequences. There needs to be a tad of intelligence in play when adding a circuit, expecting to draw 100 amps from the fuse box inside the car just because you can add a 100 amp fuse is likely to end badly..:oops:
     
  9. Nigel

    Nigel Well-Known Member

    Messages:
    5,322
    Likes Received:
    2,296
    Location:
    Devon
    Country:
    United Kingdom
    Dash Cam:
    Gitup Git3, Mini 0806
    Yes, they will certainly make sure that the total load that can get through the fuses is no more than the total capacity of the segment. And if you make sure that you retain the original fuse ratings and make sure that any taps are taken from after the original fuses by putting the fuse taps the correct way around then you know for sure that everything is safe.
     
  10. Hillbilly

    Hillbilly Well-Known Member

    Messages:
    1,548
    Likes Received:
    220
    Country:
    Australia
    To answer this very old question, the correct way is the second picture. When you insert a fuse in a circuit you apply voltage on one side and take it out the other or the fuse wont work, In the first pic the V has to go first through the 30 amp fuse and then out the 5 amp one to get to the wire. So why do you need 2 fuses on what has been made effectively one circuit by inserting it incorrectly.
    In the second pic the V is coming in on the correct pin and being divided between the two fuses and out the other pin and the wire. If you pull either fuse V to that circuit will cease

    Anyway if you use the original plug from the camera it has a 2 amp fuse in it anyway.

    Always remember a fuse is put there to protect the vehicle from the appliance. NOT the appliance from the vehicle
     
  11. Hillbilly

    Hillbilly Well-Known Member

    Messages:
    1,548
    Likes Received:
    220
    Country:
    Australia
    Here is the ONLY correct way to insert a fuse tap No ifs or buts. addafuse correct.jpg
     
    spaceballsrules likes this.
  12. ikjadoon

    ikjadoon New Member

    Messages:
    10
    Likes Received:
    4
    Country:
    United States
  13. jokiin

    jokiin Well-Known Member Manufacturer

    Messages:
    36,101
    Likes Received:
    18,181
    Location:
    Shenzhen, China - Sydney, Australia
    Country:
    China
    Dash Cam:
    Too many ¯\_(ツ)_/¯
    what that is saying effectively is if you install a fuse tap the wrong way around the circuit is not fused at all and needs an inline fuse added, there may be situations due to clearance where it is not possible to install the tap in the correct orientation
     
    ikjadoon likes this.
  14. CDNinHH

    CDNinHH Active Member

    Messages:
    518
    Likes Received:
    176
    Country:
    Thailand
    Dash Cam:
    A118C MG600G (JooVuuX returned)A119 Shadow 1S
    I have never seen a fuse tap that does not incorporate a fuse in its design, is there such a thing?
     
  15. jokiin

    jokiin Well-Known Member Manufacturer

    Messages:
    36,101
    Likes Received:
    18,181
    Location:
    Shenzhen, China - Sydney, Australia
    Country:
    China
    Dash Cam:
    Too many ¯\_(ツ)_/¯
    even though they have a fuse if installed the wrong way around they are effectively unfused on the auxiliary circuit, the original circuit will still be protected either way
     
  16. CDNinHH

    CDNinHH Active Member

    Messages:
    518
    Likes Received:
    176
    Country:
    Thailand
    Dash Cam:
    A118C MG600G (JooVuuX returned)A119 Shadow 1S
    oh oh.....I'm not going to get into this again.
     
  17. Rajagra

    Rajagra Well-Known Member

    Messages:
    2,429
    Likes Received:
    1,808
    Country:
    United Kingdom
    Dash Cam:
    Mini0806
    Their fuse taps are clips that attach to one side of a fuse. They are not like add-a-fuses. Potentially much more risky.

    Sent from my tap-to-talk using Tapatalk
     
  18. CDNinHH

    CDNinHH Active Member

    Messages:
    518
    Likes Received:
    176
    Country:
    Thailand
    Dash Cam:
    A118C MG600G (JooVuuX returned)A119 Shadow 1S
    Ahh, ok....interesting.
     
  19. Hillbilly

    Hillbilly Well-Known Member

    Messages:
    1,548
    Likes Received:
    220
    Country:
    Australia
    They are no better than stuffing a wire down the side of a fuse A recipe for disaster if ever I saw one.

    The picture I posted on page 3 is the correct way to do it
     
  20. CDNinHH

    CDNinHH Active Member

    Messages:
    518
    Likes Received:
    176
    Country:
    Thailand
    Dash Cam:
    A118C MG600G (JooVuuX returned)A119 Shadow 1S
    So....not wanting to start this all over again, because you have your opinion on it, but without using a multi-meter how do you know which side of a tap is the direct side ( as shown in blue on the left side in your diagram) is there any markings on the those taps that show that is the linked side as opposed to the right side being the linked side?
     
Loading...

Share This Page