atv wiring help

Discussion in 'The Projects Forum' started by bansheedave, Sep 6, 2010.

  1. bansheedave

    Thread Starter New Member

    Sep 6, 2010
    8
    0
    i have an 85 kawasaki klt160 three wheeler. my problem is the lighting. the lighting coil lost its resistance so it puts out full voltage. burning out the lights. its a simple set-up wiring wise. the repair manual says (ac lighting voltage/ 3000 r/min) 11.5 volts to im guessing 12 volts and the coil resistance is .8 - 1.5 Ω. thats all the book states. a new coil will cost $300 or more which i dont and wont spend. i want to put an inline resistor in the harness. is it possible to do and if so, what resistor should i use?

    thanks, dave

    ps, it puts out 30 to 40 volts right now
     
  2. marshallf3

    Well-Known Member

    Jul 26, 2010
    2,358
    201
    It won't be the lighting coil, there's a rectifier/regulator assembly in there somewhere that's gone bad.

    Some used separate rectifiers and regulators, most lumped them together into a small black module.
     
  3. bansheedave

    Thread Starter New Member

    Sep 6, 2010
    8
    0
  4. bansheedave

    Thread Starter New Member

    Sep 6, 2010
    8
    0
    this is the diagram. there isnt a rectifier. the manual says to take a reading off the lighting wire, the single lead coming from the stator going to the light switch. it says to put the meter to the x 1 ohm range, put the meter leads from the one wire and the lead to ground and measure the resistance which i have done. the meter read 0.0
    i also ran a test from the lights while the bike is running as per the manual. it states the voltage should be low and rise when the engine runs up to 3000 rpm. it doesnt specify low voltage but i would assume 5 or 6 volts and rise to 11.5 to 12.5 votls as motor increases. my readings showed 9 volts and when i increased engine speed it went up to 35 to 40 volts.
     
    Last edited: Sep 7, 2010
  5. Dyslexicbloke

    Active Member

    Sep 4, 2010
    420
    19
    Did you have the right load on it at the time of the test IE both bulbs.
    If there really isnt any rectifyer / regulator and the bulbs are on an AC that is current limited by the stator windings then without any load you would expect to see much higher voltages.
    This would be a very strange arrangement though.
    I'm curious the 30 volts, AC or DC and what sort of meeter did you use?
    Al
     
  6. bansheedave

    Thread Starter New Member

    Sep 6, 2010
    8
    0
    according to the manual, its ac voltage. i used a digital muli-meter and followed the book. there isnt any load applied. there arent any bulbs as they keep blowing. the the reading off the stator is with the bike not running. the reading from the wires up the harness to get voltage reading is with the bike running
     
  7. bansheedave

    Thread Starter New Member

    Sep 6, 2010
    8
    0
  8. bansheedave

    Thread Starter New Member

    Sep 6, 2010
    8
    0
    i was reading the book over more. it says it requires a 12volt 45 watt headlight and a 12 volt 8 watt tail light bulb. the coil puts out ac voltage which means the bulbs will be ac, correct? ive been putting in automotive bulbs which are dc, correct? im throwing out ideas. maybe the coil is working fine, i must be using the wrong bulbs?
     
  9. marshallf3

    Well-Known Member

    Jul 26, 2010
    2,358
    201
    When it comes to incandescent lamps there are no real distinctions between AC or DC.

    Pretty cheap circuit that, and if the lighting coil were going out you'd expect the voltage to drop, not increase.

    Adding a series resistor or more load to the circuit might prove to be a temporary band-aid solution but the magneto is apparently failing and who knows what it will do next - and when?

    If the bulbs are good and of the proper voltage and wattage I'm somewhat lost as to any simple suggestions.
     
  10. bansheedave

    Thread Starter New Member

    Sep 6, 2010
    8
    0
    i figured it out and with the help of everyone. because of the simplistic system, it needs two bulbs in working order to make the lighting system work right. if one bulb blows it overloads the other bulb causing it to blow. i just went out and proved that. i put one bulb in and it blew. put in two bulbs, and it worked perfectly. an odd setup for sure. thanks everyone for the help. now i dont need to put a resistor or anything else in-line.
     
  11. Dyslexicbloke

    Active Member

    Sep 4, 2010
    420
    19
    Just a thought but why dont you add a rectifier and voltage regulator.
    If you did that the cascading bulb fail problem would go away.

    You are only talking about 4 1/2 amps or so ... you could probably get one all packaged in one unit, designed for another bike
    I say bike because car ones usuly control the alternator field where as bikes, particulaly older ones, generally hav PM alternators like your setup.

    You could build one but by the time you get a good meaty reg and a heat sink and pot it .... bike breakers would be far cheaper I expect.

    Al
     
  12. bansheedave

    Thread Starter New Member

    Sep 6, 2010
    8
    0
    i might just do that. sounds like an easy fix and i can get the parts anywhere. thanks for the idea.
     
Loading...