connecting lights with single wire to battery

Discussion in 'Electrical' started by jbrewer, Sep 4, 2009.

  1. jbrewer

    jbrewer New Member

    okay, really dumb question here, but I'm so ignorant, I can't even formulate a search to satisfactorily answer the question (and yes, i've tried).

    I have a headlight and a taillight, each with a SINGLE WIRE. I want to connect them to a battery. How do I do this? My Neanderthal knowledge of electrical circuits informs me that I need two wires, one to go the the positive and one to the negative terminal, to complete the circuit.

    What am I missing here? Please help.:dunce:

    Thanks,

    Steve
     

  2. HoughMade

    HoughMade Guest

    Connect the positive of the battery to the sinlge wire (though the switch of you choice). Connect the negative of the battery to the frame and make sure the light is attached firmly to the frame.

    -or-

    Connect the positive as above and run a wire from the negative to the body of the light.
     
  3. motorpsycho

    motorpsycho Active Member

    good luck with this.
    i've been trying to get a headlight to work on my bike for 3 weeks using the white wire.
    i even re-wired my light so it has 2 wires (a + and a -). every time i ground the - to the frame, handlebars, sissy bar...anywhere on my bike that is metal... it kills the motor. for some reason there is 5 volts of juice running through my frame when the engine is running. so when i hook up the ground, it shorts out the ignition and kills the motor.
    yes, my motor is mounted to the frame with rubber pads and i even tired to isolate the headlight with rubber...to keep the mount from actually touching any part of the bike. but since my frame and all components get a positive charge with the motor running, when ever i hook the ground wire to the frame it's the same as if i push the kill switch.
    i am no dummy and i have tired EVERYTHING to get it to work. i even tired hooking up a wheel driven generator to get away from using the white wire. as soon as i got the motor running, the 6 volt wheel generator blew because of the positive charge. for some reason, my bike does not have an actual ground when the motor is running.
    i can not figure it out and i've tried everything.
    i have messed with electronics, ignition systems, charging systems and electrical for years and this one has me puzzled.
    i hooked the headlight to a 6 volt battery charger and it works great so this is not a problem with the headlight.
    if you get yours to work, let me know how you did it.

    i was told that if you hook a headlight to the white wire, it will take away some of the power going to your cdi box. the white wire is hooked directly to the magneto, just like the blue wire. the magneto output is like 6 volts so trying to send 6 volts to the cdi, and then 6 volts to the light...something has to NOT work because there isn't enough voltage to run both.
     
    Last edited: Sep 5, 2009
  4. flaustin

    flaustin New Member

    My guess is you have a bulb that draws to much current. From what I understand the "generator" on these motors only put out about 1/2 an Amp OR 500 ma (milliamp) at 6 volts and 1/2 amp that's 3 watts. (amps X volts = watts). To run on the generator you will need a 6 volt lamp of LESS than 3 watts. Suggestion would be to switch to a LED lamp. Generally they draw a small amount of current.

    Putting a large wattage bulb on the white wire is the same as shorting (connecting to ground) the white wire to ground. this will kill the motor!
     
  5. Scotchmo

    Scotchmo Member

    The power coming out of the white wire is AC. The ignition uses the negative cycle for itself. The positive cycle can be tapped to run a small LED light or run through a rectifier diode to keep a 6v battery charged. An LED only uses a half cycle so it will not kill the ignition when hooked up directly to the white wire in the correct direction. If you want to run large LEDs or anything else, run it off a small 6v motorcycle battery and use the white wire/rectifier diode to keep the battery charged. If you run an LED directly off the wire, it will experience wide voltage fluctuations and could run dim at idle or blow out at higher rpm. Some LED lights may tolerate the voltage fluctuations, some may not. Having the battery in the circuit will regulate the voltage.
     
    Last edited: Sep 5, 2009
  6. motorpsycho

    motorpsycho Active Member

    my other thought is to get a new style battery operated led light.
    take the guts out of it, and put them in my cool chrome bullet headlight and just use whatever battery is needed to power the led light.
    I'm going to scrap the idea of even trying to hook anything to the white wire.
    as someone else said, the bulb that is in my headlight now is 6 volts @ 3 amps...which is too much to run off of the white wire.
     
  7. jbrewer

    jbrewer New Member

    Thanks and possible suggestion

    Houghmade

    Thanks for your suggestion. Now I understand, and it works.

    Motorpsycho and others, fortunately, I'm not trying to run lights off the white wire. I'm using a battery pack for each DC light and plan to replace the bulbs with LEDs to boost the brightness a little (these lights are mainly cosmetic, anyway; I don't intend to ride this at night). I've seen a long string of posts arguing the pros and cons of using the white wire to power lights. I seem to recall someone saying that too much juice is stolen from the sparkplug. But you guys know a lot more about this than I do.

    Good luck,

    Steve
     
  8. machiasmort

    machiasmort Active Member

    Don't know if your your in the city or sticks?

    In the sticks I suggest battery power all the way.

    I live in NY and the Cops are tough here. I'm using in series 3 LEDs, inorder to give my motor a reason to be running (cheaper than batteries Sir)!

    If you try again w/WW, it's the amps drawn that effect the motor not volts! Use small LEDS, they are not expensive. Trial and error till you get the right size to run!
     
  9. customcruiser

    customcruiser Member

    ill hook mu lighting system up tommorrow and take a picture and post it tommorrow night and u can see my lighting system i have some standard led lights bought from bike shop for around the city
    but i have nthis good light system i use when i go out of town or along the river where i cant see.
     
  10. customcruiser

    customcruiser Member

    ill hook mu lighting system up tommorrow and take a picture and post it tommorrow night and u can see my lighting system i have some standard led lights bought from bike shop for around the city
    but i have nthis good light system i use when i go out of town or along the river where i cant see.and i have used the white wire to run lights before
     
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