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

Add-A-Circuit/ Fuse question

Discussion in 'Lighting' started by cverneau, Feb 18, 2012.

  1. Feb 18, 2012 at 6:58 AM
    #1
    cverneau

    cverneau [OP] Well-Known Member

    Joined:
    Feb 22, 2011
    Member:
    #51619
    Messages:
    282
    Gender:
    Male
    First Name:
    Craig
    Cheshire, CT.
    Vehicle:
    11 Access Cab 4cyl 4x4 Auto
    AVS In-Channel Window Deflectors, AVS Rear Window Sun/Rain Deflector, EGR Front Hood Deflector, Weathertech Digital Fit Floor Liners With TRD Off Road Decals, TonnoPro Tri-Fold Cover, Coverking Black Neoprene Front Seat Covers & Front & Rear Center Console Covers, Black With Red Stitched TRD Head Rest Covers, Rear Grey Neoprene Wet Okole Seat Covers, Black Front Door Handle Pull Covers, Husky Custom Molded Mud Flaps, Devil Horns Of Fire On Satoshi, 7" Off Road Lights Mounted Behind Grill, Pop N Lock 5300, Seatbelt Chime Off, Interior & Exterior Led's, Cubby & Drink Holder Amber LED's, Infinity Reference #9633 6X9 Front Speakers, Solar-Gard HP Smoke 35% Tint, De-badged & Pinstripe Removal, Sun Visor Stickers Removed, Illuminated 4x4 Switch, ImMrYo Rear-View Mirror Lift Bracket, Ultragauge, TRD Aluminum Skid Plate, Bed Storage Cubby Locks Mod, Additional D-Rings In Bed, Rubber Bed Mat, Intermittent Wiper Stalk, Black Vinyl Arm Rest Mod, Secondary Air Filter Removal Mod, Spare Tire Rod Alignment Tube Mod, 14" Antenna Mod, Tailgate Theft Mod, DTRL Wire Jumper Mod, Parking Lights As Turn Signals Mod, Under Hood LED Strip Lighting Mod, 30 Watt Reverse Bulbs, PIAA 510's With LED's In Fog Locations, Cree LED Flood lights In Rear Bumper, Burner Bedlights In Bed Cubby's, Avid Light Bar, Horn Relocation Mod, Rear TSB Springs, Bilstein 5100's on all four corners - front set at 0.85", Cooper Discoverer ATP - 265-75R/16, Pioneer AVH-X3700BHS Head Unit With Microbypass, Added USB Charging Ports Under Dash.
    I'm installing PIAA 510's in my fog locations and some Wal-Mart Burners in the cubby's for bed lights. I picked up two add-a-fuses to tap into two slots that are only powered when the ignition is on. They will be for the power to the new switches and their illumination. Here's my question:
    I know the fuse in the first slot on the add-a-fuse will be the original size as the location I'm tapping into, but what size fuse should be used for the power to the switches and the illumination of those switches??
     
  2. Feb 18, 2012 at 12:52 PM
    #2
    iroc409

    iroc409 Well-Known Member

    Joined:
    Jul 8, 2009
    Member:
    #19444
    Messages:
    446
    Gender:
    Male
    Washington
    Vehicle:
    A red one
    By power to the switches, are you talking about the power circuit to activate the relay? If so, a 2A fuse should be more than enough. It's what I have used to activate two relays.
     
  3. Feb 18, 2012 at 3:48 PM
    #3
    cverneau

    cverneau [OP] Well-Known Member

    Joined:
    Feb 22, 2011
    Member:
    #51619
    Messages:
    282
    Gender:
    Male
    First Name:
    Craig
    Cheshire, CT.
    Vehicle:
    11 Access Cab 4cyl 4x4 Auto
    AVS In-Channel Window Deflectors, AVS Rear Window Sun/Rain Deflector, EGR Front Hood Deflector, Weathertech Digital Fit Floor Liners With TRD Off Road Decals, TonnoPro Tri-Fold Cover, Coverking Black Neoprene Front Seat Covers & Front & Rear Center Console Covers, Black With Red Stitched TRD Head Rest Covers, Rear Grey Neoprene Wet Okole Seat Covers, Black Front Door Handle Pull Covers, Husky Custom Molded Mud Flaps, Devil Horns Of Fire On Satoshi, 7" Off Road Lights Mounted Behind Grill, Pop N Lock 5300, Seatbelt Chime Off, Interior & Exterior Led's, Cubby & Drink Holder Amber LED's, Infinity Reference #9633 6X9 Front Speakers, Solar-Gard HP Smoke 35% Tint, De-badged & Pinstripe Removal, Sun Visor Stickers Removed, Illuminated 4x4 Switch, ImMrYo Rear-View Mirror Lift Bracket, Ultragauge, TRD Aluminum Skid Plate, Bed Storage Cubby Locks Mod, Additional D-Rings In Bed, Rubber Bed Mat, Intermittent Wiper Stalk, Black Vinyl Arm Rest Mod, Secondary Air Filter Removal Mod, Spare Tire Rod Alignment Tube Mod, 14" Antenna Mod, Tailgate Theft Mod, DTRL Wire Jumper Mod, Parking Lights As Turn Signals Mod, Under Hood LED Strip Lighting Mod, 30 Watt Reverse Bulbs, PIAA 510's With LED's In Fog Locations, Cree LED Flood lights In Rear Bumper, Burner Bedlights In Bed Cubby's, Avid Light Bar, Horn Relocation Mod, Rear TSB Springs, Bilstein 5100's on all four corners - front set at 0.85", Cooper Discoverer ATP - 265-75R/16, Pioneer AVH-X3700BHS Head Unit With Microbypass, Added USB Charging Ports Under Dash.
    Yes. it's to power the circuit to activate the relays. I knew it would be a small amp fuse as it's just powering the relay and illuminating the switch LED, but I didn't think it would be as low as that. So, If I have 5A fuses lying around, then I guess I'm good to go....
     
  4. Feb 19, 2012 at 12:22 PM
    #4
    iroc409

    iroc409 Well-Known Member

    Joined:
    Jul 8, 2009
    Member:
    #19444
    Messages:
    446
    Gender:
    Male
    Washington
    Vehicle:
    A red one
    I'd go below 5A if you can, just to be safe. 3A fuses are pretty easy to come by. 2A is a little harder, but I found a stash of them so that's what I use.
     
  5. Mar 9, 2012 at 7:14 PM
    #5
    Rich91710

    Rich91710 Well-Known Member

    Joined:
    Feb 23, 2012
    Member:
    #73470
    Messages:
    16,404
    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
    +1

    The important thing to remember is that the primary job of the fuse is not to protect the items connected to power. The job of the fuse is to protect the wiring from the power source to the accessory.
    If the wiring is rated for 10a, then use an 8a fuse. Never use a fuse that is more than 80% of the design spec for the circuit.
    Installing a larger fuse because one blows is stupid and asking for a fire.

    But given adequate wiring size, always use the smallest fuse that will support the item being powered. Again, the 80% rule applies... if the item draws 4 amps, then do not use a fuse smaller than 5a.

    So actual load < 80% of fuse rating
    Fuse rating < 80% of wire gauge limit

    4amps would be about 55 watts to give an idea. A motorcycle headlight circuit is normally a 10a fuse.

    Capacities:

    24 = 3.5a = 2.8a fuse = 2.24a load continuous
    22 = 7a = 5.6a fuse = 4.48a load
    20 = 11a = 8.8a fuse = 7.04a load
    18 = 16a = 12.8a fuse = 10.24a load continuous
    16 = 22a = 17.6a fuse = 14.08a load continuous
    14 = 32a = 25.6a fuse = 20.48a load continuous
    12 = 41a = 32.8a fuse = 26.24a load continuous
    10 = 55a = 44a fuse = 35.2a load continuous
    8 = 73a = 58.4a fuse = 46.72a load continuous
    6 = 101a = 80.8a fuse = 64.64a load continuous
    4 = 135a = 108a fuse = 86.4a load continuous
     
  6. Mar 11, 2012 at 6:43 AM
    #6
    cverneau

    cverneau [OP] Well-Known Member

    Joined:
    Feb 22, 2011
    Member:
    #51619
    Messages:
    282
    Gender:
    Male
    First Name:
    Craig
    Cheshire, CT.
    Vehicle:
    11 Access Cab 4cyl 4x4 Auto
    AVS In-Channel Window Deflectors, AVS Rear Window Sun/Rain Deflector, EGR Front Hood Deflector, Weathertech Digital Fit Floor Liners With TRD Off Road Decals, TonnoPro Tri-Fold Cover, Coverking Black Neoprene Front Seat Covers & Front & Rear Center Console Covers, Black With Red Stitched TRD Head Rest Covers, Rear Grey Neoprene Wet Okole Seat Covers, Black Front Door Handle Pull Covers, Husky Custom Molded Mud Flaps, Devil Horns Of Fire On Satoshi, 7" Off Road Lights Mounted Behind Grill, Pop N Lock 5300, Seatbelt Chime Off, Interior & Exterior Led's, Cubby & Drink Holder Amber LED's, Infinity Reference #9633 6X9 Front Speakers, Solar-Gard HP Smoke 35% Tint, De-badged & Pinstripe Removal, Sun Visor Stickers Removed, Illuminated 4x4 Switch, ImMrYo Rear-View Mirror Lift Bracket, Ultragauge, TRD Aluminum Skid Plate, Bed Storage Cubby Locks Mod, Additional D-Rings In Bed, Rubber Bed Mat, Intermittent Wiper Stalk, Black Vinyl Arm Rest Mod, Secondary Air Filter Removal Mod, Spare Tire Rod Alignment Tube Mod, 14" Antenna Mod, Tailgate Theft Mod, DTRL Wire Jumper Mod, Parking Lights As Turn Signals Mod, Under Hood LED Strip Lighting Mod, 30 Watt Reverse Bulbs, PIAA 510's With LED's In Fog Locations, Cree LED Flood lights In Rear Bumper, Burner Bedlights In Bed Cubby's, Avid Light Bar, Horn Relocation Mod, Rear TSB Springs, Bilstein 5100's on all four corners - front set at 0.85", Cooper Discoverer ATP - 265-75R/16, Pioneer AVH-X3700BHS Head Unit With Microbypass, Added USB Charging Ports Under Dash.
    I found the 2A fuses sold loose at the local hardware store - everything works perfectly.
     
To Top