1. Welcome to Tacoma World!

    You are currently viewing as a guest! To get full-access, you need to register for a FREE account.

    As a registered member, you’ll be able to:
    • Participate in all Tacoma discussion topics
    • Communicate privately with other Tacoma owners from around the world
    • Post your own photos in our Members Gallery
    • Access all special features of the site

Fuse for aux lights gets hot

Discussion in 'Lighting' started by KeithB, Jul 19, 2012.

  1. Jul 19, 2012 at 8:30 AM
    #1
    KeithB

    KeithB [OP] Well-Known Member

    Joined:
    Jan 6, 2009
    Member:
    #12299
    Messages:
    645
    Gender:
    Male
    First Name:
    Keith
    Cheshire, CT
    Vehicle:
    SWB '09 Tacoma DCSB Sport 4x4
    Wheels and Tires: 17x8" Ultra Goliath wheels with P285/70R17 Nitto Terra Grappler G2, Suspension: Icon coilovers set at 2.5", TC UCA's, 1.5" lift 3 leaf pack with overload left in, 3* shims, carrier bearing drop, Bilstein 5100 B110 rear shocks Other: TRD SS exhaust, Ottonavi H/U with Sat radio, bluetooth, ipod interface, DVD, Navigation Accessories: Toyota roof rack, black Toyota running board steps, cargo divider, weathertech floor liners, Literider roll up soft tonneau, thule bars over tonneau Cosmetic: window tint, grillcraft black mesh upper/lower grill, eyelids, tinted tails and third brake light, vinyl armrest in doors Lighting: fogs only mod, bed lights in pockets, back up lights, amber interior accent lighting, amber 10" LED light bar in hood scoop, 33" LED bar behind the lower grill, amber lamin-x on fog lights
    Is this normal? It's the 15 amp fuse that runs from positive battery terminal to the relay (terminal #30). I have 3 Hella 700ff lights that run off one wire/fuse. The fuse casing (inline glass tube style fuse) isn't too hot to hold but the fuse itself is very hot. If this is not normal, what might I have done wrong? What would cause the fuse to get hot? I switched it to a 20 amp fuse since I am running 3 lights instead of the two that the kit came with. Do I need lower guage wire for the additional current. I belieive the kit came with 14 guage wire. Everything is wired as per the instructions and works just fine except the fuse getting hot is suspisious.

    Lights
    to ground
    to relay #87

    I have a 40 amp relay
    30 - to battery with in line fuse
    87 - to lights
    86 - to switch
    85 - to ground

    Rocker switch in dash
    to ground
    to 2.5 amp fuse
    to relay #86
     
  2. Jul 19, 2012 at 1:38 PM
    #2
    KeithB

    KeithB [OP] Well-Known Member

    Joined:
    Jan 6, 2009
    Member:
    #12299
    Messages:
    645
    Gender:
    Male
    First Name:
    Keith
    Cheshire, CT
    Vehicle:
    SWB '09 Tacoma DCSB Sport 4x4
    Wheels and Tires: 17x8" Ultra Goliath wheels with P285/70R17 Nitto Terra Grappler G2, Suspension: Icon coilovers set at 2.5", TC UCA's, 1.5" lift 3 leaf pack with overload left in, 3* shims, carrier bearing drop, Bilstein 5100 B110 rear shocks Other: TRD SS exhaust, Ottonavi H/U with Sat radio, bluetooth, ipod interface, DVD, Navigation Accessories: Toyota roof rack, black Toyota running board steps, cargo divider, weathertech floor liners, Literider roll up soft tonneau, thule bars over tonneau Cosmetic: window tint, grillcraft black mesh upper/lower grill, eyelids, tinted tails and third brake light, vinyl armrest in doors Lighting: fogs only mod, bed lights in pockets, back up lights, amber interior accent lighting, amber 10" LED light bar in hood scoop, 33" LED bar behind the lower grill, amber lamin-x on fog lights
    bueller? bueller? bueller? bueller? bueller? bueller? bueller? bueller?
     
  3. Jul 19, 2012 at 1:43 PM
    #3
    wmdpowell

    wmdpowell Well-Known Member

    Joined:
    Nov 30, 2010
    Member:
    #46971
    Messages:
    954
    Gender:
    Male
    First Name:
    Bill
    Selkirk, NY
    Vehicle:
    4x4 reg cab, 5 speed
    Better tires Hurcules Terra Track, trimmed front mud flaps, (access limited tonneau-took off) softopper, ats running boards, Piaa fogs, window vents, Wireless thermometer, extra bed rings, valley hitch
    Might 86 and 87 be reversed? I don't think your lights would work then though.
     
  4. Jul 19, 2012 at 3:52 PM
    #4
    KeithB

    KeithB [OP] Well-Known Member

    Joined:
    Jan 6, 2009
    Member:
    #12299
    Messages:
    645
    Gender:
    Male
    First Name:
    Keith
    Cheshire, CT
    Vehicle:
    SWB '09 Tacoma DCSB Sport 4x4
    Wheels and Tires: 17x8" Ultra Goliath wheels with P285/70R17 Nitto Terra Grappler G2, Suspension: Icon coilovers set at 2.5", TC UCA's, 1.5" lift 3 leaf pack with overload left in, 3* shims, carrier bearing drop, Bilstein 5100 B110 rear shocks Other: TRD SS exhaust, Ottonavi H/U with Sat radio, bluetooth, ipod interface, DVD, Navigation Accessories: Toyota roof rack, black Toyota running board steps, cargo divider, weathertech floor liners, Literider roll up soft tonneau, thule bars over tonneau Cosmetic: window tint, grillcraft black mesh upper/lower grill, eyelids, tinted tails and third brake light, vinyl armrest in doors Lighting: fogs only mod, bed lights in pockets, back up lights, amber interior accent lighting, amber 10" LED light bar in hood scoop, 33" LED bar behind the lower grill, amber lamin-x on fog lights
    naa, the wiring is correct, just not sure the fuse is supposed to get hot. Thinking I might need heavier guage wire for the extra load (3 vs 2 lights).
     
  5. Jul 19, 2012 at 5:27 PM
    #5
    Rich91710

    Rich91710 Well-Known Member

    Joined:
    Feb 23, 2012
    Member:
    #73470
    Messages:
    16,477
    Gender:
    Male
    First Name:
    Rich
    Los Angeles
    Vehicle:
    08 Base
    Satoshi with FJ badge, factory cruise, factory intermittent wipers, Redline Tuning hood-lift struts, Hellwig Swaybar, Rosen DVD-Nav
    Poor contact on the fuse will cause that.
    I do NOT like inline glass fuse holders for this reason... damned near burned out my '69 Camaro.

    #1 - Switch to a blade type fuse and fuse holder.

    #2 - 15a fuse should be carrying no more than 12 amps, wire should be 14ga or larger.
    12 amps is about 144 watts.... Those Hellas are 55 watts each, you're pulling too much through the fuse and wire.

    Three 55 watt lights is 165 watts, roughly 14 amps.
    14 amp continuous requires a 20amp fuse and 12ga wire (80% rule). Anything smaller may run hot.
     
  6. Jul 19, 2012 at 5:33 PM
    #6
    brutalguyracing

    brutalguyracing BIG DADDY

    Joined:
    Jun 28, 2009
    Member:
    #19000
    Messages:
    24,005
    Gender:
    Male
    F.U> GUYZ
    broken mods
    well done sir.......... rep to you
     
  7. Jul 19, 2012 at 6:10 PM
    #7
    KeithB

    KeithB [OP] Well-Known Member

    Joined:
    Jan 6, 2009
    Member:
    #12299
    Messages:
    645
    Gender:
    Male
    First Name:
    Keith
    Cheshire, CT
    Vehicle:
    SWB '09 Tacoma DCSB Sport 4x4
    Wheels and Tires: 17x8" Ultra Goliath wheels with P285/70R17 Nitto Terra Grappler G2, Suspension: Icon coilovers set at 2.5", TC UCA's, 1.5" lift 3 leaf pack with overload left in, 3* shims, carrier bearing drop, Bilstein 5100 B110 rear shocks Other: TRD SS exhaust, Ottonavi H/U with Sat radio, bluetooth, ipod interface, DVD, Navigation Accessories: Toyota roof rack, black Toyota running board steps, cargo divider, weathertech floor liners, Literider roll up soft tonneau, thule bars over tonneau Cosmetic: window tint, grillcraft black mesh upper/lower grill, eyelids, tinted tails and third brake light, vinyl armrest in doors Lighting: fogs only mod, bed lights in pockets, back up lights, amber interior accent lighting, amber 10" LED light bar in hood scoop, 33" LED bar behind the lower grill, amber lamin-x on fog lights

    Well said. Thank you. Kind of what I thought but didn't know the technical stuff to back it up.

    So I should run 12ga wire from lights to relay as well as the battery to relay?

    Also, already planned to switch to blade type fuse. Have a fuse block on order for all my aux lighting. The glass tube type is what came with the kit.
     
  8. Jul 19, 2012 at 6:18 PM
    #8
    Rich91710

    Rich91710 Well-Known Member

    Joined:
    Feb 23, 2012
    Member:
    #73470
    Messages:
    16,477
    Gender:
    Male
    First Name:
    Rich
    Los Angeles
    Vehicle:
    08 Base
    Satoshi with FJ badge, factory cruise, factory intermittent wipers, Redline Tuning hood-lift struts, Hellwig Swaybar, Rosen DVD-Nav
    Yup. 12ga from the battery to the (20a) fuse holder to the relay to the lights AND to ground.
    18ga or 20ga from a switched power source through a 5a fuse to the dash switch to pin 85 or 86 on the relay, same size from the other (86 or 85) to ground.

    The three basic rules that will help ensure a safe build:

    1 - The purpose of the fuse is to protect the wire... it must be sized to protect the smallest wire, switch, or relay.

    2 - Nothing in the system may continually carry more than 80% of it's rated capacity.

    3 - Often overlooked... What goes in must come out. The current at any point in a series circuit is identical. If you are drawing 15a through the relay, you are also pulling 15a through the ground wire.



    #3 is one that bites people often. They'll run 4ga wires to a rack of amps... then they'll tie all 4 amps to a single 6ga ground wire. The ground wire just became the fuse.
     
To Top