***Login to the Forum here ***

Support FSC and see no ads! - Click Here
Results 1 to 5 of 5

How many amps does two H3 100watt bulbs pull?

This is a discussion on How many amps does two H3 100watt bulbs pull? within the Technical / Maintenance forums, part of the General Discussion category; I want to put these in the fog lights on my truck and right now I have 55 watt with ...

  1. #1
    Registered User go-dwr's Avatar
    Join Date
    Dec 2005
    Location
    Ohio
    Posts
    32

    How many amps does two H3 100watt bulbs pull?


    Support FSC and see no ads! - Click Here
    I want to put these in the fog lights on my truck and right now I have 55 watt with 15 amp inline fuse from the battery, so would this setup be ok for two H3 halogen 100 watt bulbs replacing the 55 watt ones or do I need a 30 amp inline fuse?

  2. #2
    Supporting Member Bob T's Avatar
    Join Date
    Mar 2004
    Location
    Lompoc, CA
    Age
    70
    Posts
    2,877

    Re: How many amps does two H3 100watt bulbs pull?

    Quote Originally Posted by go-dwr
    I want to put these in the fog lights on my truck and right now I have 55 watt with 15 amp inline fuse from the battery, so would this setup be ok for two H3 halogen 100 watt bulbs replacing the 55 watt ones or do I need a 30 amp inline fuse?
    200 watts at 12 volts would be 17 amps. I thing you want to upgrade the fuse AND the wiring.

    Amps = Watts/Volts
    '04 Silverado 1/2 ton 2WD ext. cab dk. grey. 5.3 liter, locking diff. XLerator exhaust - offbrand but throaty. Borgeson intermediate shaft, Bilstein HD shocks.

    KJ6LFD

  3. #3
    Registered User go-dwr's Avatar
    Join Date
    Dec 2005
    Location
    Ohio
    Posts
    32

    Re: How many amps does two H3 100watt bulbs pull?

    Thanks I will get the bigger fuse and wiring and I already have it hooked to a 30 amp relay with seperate wires for each light with 14ga or 16ga wire but the relay is powered from 15amp inline fuse that I will upgrade to 30amp inline. Is the 14ga or 16ga seperate wires to the lights ok or should it be a 12ga wire to each light?

  4. #4
    Supporting Member Bob T's Avatar
    Join Date
    Mar 2004
    Location
    Lompoc, CA
    Age
    70
    Posts
    2,877

    Re: How many amps does two H3 100watt bulbs pull?

    Here is a link to a wire size / length / amps table for 12 volt systems:
    http://www.msinter.net/tradingcave/windpower/wiring.htm
    Too small a wire can overheat and melt the insulation.

    A longer wire causes more voltage drop than a shorter wire; less volts means less light output. Compensate by using a larger diameter wire.

    The only problems with too big a wire is cost and it's harder to run around the vehicle.

    Be sure the wire is well supported away from exhaust and doesn't rub against anything. If it goes through a hole, use a grommet.

    If something goes wrong and your truck burns, don't come out here to kick my a$$.
    Last edited by Bob T; 01-01-2006 at 11:07 AM.
    '04 Silverado 1/2 ton 2WD ext. cab dk. grey. 5.3 liter, locking diff. XLerator exhaust - offbrand but throaty. Borgeson intermediate shaft, Bilstein HD shocks.

    KJ6LFD

  5. #5
    1972 Chevy Beauville Diamond Jim's Avatar
    Join Date
    Feb 2004
    Location
    coastal NC
    Posts
    1,460

    Re: How many amps does two H3 100watt bulbs pull?

    Amps X Volts = Watts

    Watts / Amps = Volts

    Watts / Volts = Amps

    Q.E.D.
    Last edited by Diamond Jim; 01-01-2006 at 12:24 PM.
    Diamond Jim
    98 Burb, 5.7L, 2500LS, 4X4; 80 GMC 383, , Long bed; 74 Dually Flatbed 350; 73 Short bed 350 4X4; 41 Chevy Master Deluxe, 327/375hp Rochester FI; 89 Fleetwood Bounder, 2 ton Chevy Chassis, 454/TH425

 

 

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •