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Technical Difference in amp draw...

Discussion in 'The Hokey Ass Message Board' started by sidevalve8ba, Feb 2, 2020.

  1. Can someone tell me how much difference there is in amp draw between a regular 7 inch sealed beam headlight and a halogen sealed beam of the same size?
     
  2. Truck64
    Joined: Oct 18, 2015
    Posts: 5,325

    Truck64
    Member
    from Ioway

    Tungsten vs. Halogen, I don't believe there is enough difference to matter in terms of say a stock wiring harness. Seem to recall it's about 5 watts per. I'll let you do the arithmetic/conversion.
     
  3. squirrel
    Joined: Sep 23, 2004
    Posts: 59,261

    squirrel
    Member

    lot more than 5 watts per filament. try 65 watts on high beam, 35 on low beam.
     
  4. amps and wattage are different...

    Take your watts divided by the volts equals your amperage, So 65 watts is equal to about 5.5 amps on a 12v system
     
  5. squirrel
    Joined: Sep 23, 2004
    Posts: 59,261

    squirrel
    Member

    Halogen makes more light, does not draw more power. They just add a gas to the bulb, which allows the tungsten filament to burn hotter without burning out. Nothing magic...just chemistry in action.
     
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  6. Truck64
    Joined: Oct 18, 2015
    Posts: 5,325

    Truck64
    Member
    from Ioway

    No, I said the difference between Tungsten and Halogen is only about 5 watts. Not enough to matter, well within the limits of original wiring harness and switches.
     
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  7. squirrel
    Joined: Sep 23, 2004
    Posts: 59,261

    squirrel
    Member

    Oh, sorry, I misunderstood your post.
     
  8. JeffB2
    Joined: Dec 18, 2006
    Posts: 9,653

    JeffB2
    Member
    from Phoenix,AZ

    A common complaint when switching to 12 volts from 6 volts is Halogen headlights being dimmer than expected I followed the advice here and WOW! what a change for the better on my '54 ! Scroll down to the section "A River Runs through it" https://watsons-streetworks.com/a-current-topic/ You can also see a before and after video on youtube.com
     
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  9. JeffB2
    Joined: Dec 18, 2006
    Posts: 9,653

    JeffB2
    Member
    from Phoenix,AZ

  10. It depends on the actual wattage of the lamp. Never take the rated wattage as gospel, manufacturers lie, especially from certain countries. Use an ammeter, it never lies. I have tested "18 watt" rated LED lights which were only 8 watts.
     
  11. I am wondering too if the 35 amp generator I run will support the difference or is that a non-issue?
     
  12. squirrel
    Joined: Sep 23, 2004
    Posts: 59,261

    squirrel
    Member

    that is a non issue.

    It's those damn electric fans that cause the charging system issues, most of the time
     
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  13. Blues4U
    Joined: Oct 1, 2015
    Posts: 8,058

    Blues4U
    Member
    from So Cal

    Oh Gaaawwdddd, why did he add that horrible music to that video?????
     
  14. Truck64
    Joined: Oct 18, 2015
    Posts: 5,325

    Truck64
    Member
    from Ioway

    Non-issue. Well - that's not quite true. But this is what I meant earlier about penciling out the difference.

    The important thing is that the grounds, cables, switches and connections are clean, and tight. Remember Bruce Lancaster's axiom "Clean, tight electrical connections = Happy Electrons".

    Relays are excellent, they work great, and I use them, BUT, it isn't as if they were driving around in the dark back in the day. Make sure any voltage drop is minimized. This is performed by testing cables and connections in parallel. The voltage drop is displayed as a positive number on the voltmeter.

    What happens during voltage drop testing is some of the voltage finds it easier to go around the corrosion or rust, and through the voltmeter instead.

    Figured I could get my 30 amp generator-equipped halogen headlights to work OK if the voltage drop was minimized, and I was right. They worked well, and my night vision ain't what it used to be. Then, after about 10 years added an inexpensive relay system, and because the juice was already optomized out to the headlights, it just worked even that much better. Better illumination to the sides was what I mostly noticed. A little less fluctuation when the cutout trips at idle too.

    The thing about incandescent bulbs, if the voltage/current is reduced, even just a little bit, the light output drops off a cliff.
     
  15. I too am a big fan of checking grounds. Poor grounds have slowed me up a time or two in the past so I am sure to check them now.
     
  16. Truck64
    Joined: Oct 18, 2015
    Posts: 5,325

    Truck64
    Member
    from Ioway

    The main issue is the resistance from rust and corrosion seems to roast the switches, apart from the dimmer headlights. They don't use fuses, headlight switches have an integral circuit breaker. Relays take the load off the switch, but they will work OK without them, if the wiring and connections are squared away.
     
  17. Atwater Mike
    Joined: May 31, 2002
    Posts: 11,618

    Atwater Mike
    Member

    Break Ohm's law. Go to the dark!
     
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