2006 Vulcan Nomad - Cranks over with no fuel, no spark

Discussion in 'The Garage' started by tntmo, Jul 28, 2019.

  1. tntmo

    tntmo Oops, I did it again.

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    I already had a bad fuel pump relay, and then corrosion in the fuel pump fuse block. It sure seems like a relay that is open until the bike starts, and then once it's started that relay stays open. I guess back to getting the old man eyes on the spaghetti wiring diagram. I'll let y'all know.
    #21
  2. tntmo

    tntmo Oops, I did it again.

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    I thought perhaps the resistor in the ignition switch was causing issues, Kawasaki has a 100 ohm resistor that reduces the signal to the ECU down to about 6VDC so that you can't just twist wires together to steal the bike. Sadly for me, but good for the bike...the resistor tests good and I have 6.15 VDC at the ECU with a solid battery.

    Now, that being said it doesn't start off the battery. When I hook up the booster the signal at the ECU goes up to about 8VDC and it then starts. Aha, you say! Maybe the ECU is needing more voltage for some reason. Perhaps, but when I shut the booster off and kill the engine withe the kill switch (not the key) it will start numerous times with only 6 VDC. Even less if I let the bike sit for 5-10 minutes. Once I cycle the key off and on again, no start until the booster is once again applied.

    It's a head scratcher.....
    #22
  3. KevinP65

    KevinP65 Been here awhile

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    It sure sounds like you know what you are doing as do other participants in this thread, but I am curious if you have posted your problem on a Nomad forum such as VROC. I was a member there when I had a 1600 and there are some very Vulcan-wise folks there. I checked in there a few months back when I was thinking of another Nomad and although the group seems smaller, some of the same folks that were knowledgeable then are still there. Sorry I can't be of help.
    #23
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  4. tntmo

    tntmo Oops, I did it again.

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    Thanks for the compliment....know what I'm doing, sort of! I have fair troubleshooting skills, and I don't like to give up but this one is invading my dreams. I talk about it to my wife, even though she doesn't know what the heck I'm talking about.

    I did post on two Vulcan forums. I hadn't even looked at VROC, I recall back in the AOL days (mid 90's) when that forum started. I'll post there as well.
    #24
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  5. tntmo

    tntmo Oops, I did it again.

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    I have now also checked voltage to the coils, 12+ VDC on the battery. I have removed the ignition switch and cleaned the contacts until they were flawless. I'm still having the same issues. No idea.......
    #25
  6. dtysdalx2

    dtysdalx2 Knowledge is horsepower

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    So what is the problem again? :scratch
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  7. baloneyskin daddy

    baloneyskin daddy bikaholic

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    Pull the headlight fuse and try it.
    #27
  8. tntmo

    tntmo Oops, I did it again.

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    Bike will not start on the battery. Once I hook up the charger on 40 amp boost, it will start. I can then shut off the booster, shut off the engine with the kill switch and the bike will start every time on the battery. Once I cycle the key switch off and on again, it will not start on the battery. Cycle the key off, apply booster, bike starts. Nuts.

    No change.
    #28
  9. dtysdalx2

    dtysdalx2 Knowledge is horsepower

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    Still think you need to find the voltage drop, contact or wire. Find a good schematic yet? Probe the + terminal at the starter and work your way back.

    Headlight fuse is about high current to the headlight. Suzuki's open the headlight circuit to boost current to the starter.

    I need my glasses.

    [​IMG]

    [​IMG]

    My guess is in the starter circuit relay inside the junction box.
    #29
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  10. tntmo

    tntmo Oops, I did it again.

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    I have been picking away at the wiring diagram.

    Yeah, headlight is on a relay, it’s off until the first time you start or attempt to start the bike. I tried removing all lighting from the system, no change.

    I swapped junction boxes with another Kawasaki, thought it could be the same thing...no change.
    #30
  11. dtysdalx2

    dtysdalx2 Knowledge is horsepower

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    Did you check those diodes in the junction box? Must be corrosion somewhere.

    Not sure of the connection above the battery negative, is it a diode?

    Does it turn over when it "doesn't start?"

    All I can see is the ECU won't fire the spark plugs without 6V from the ignition switch? May be bad pickup coils.
    #31
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  12. tntmo

    tntmo Oops, I did it again.

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    Yes, it’s turning over just fine, fuel pump primes. I haven’t checked the diodes, but they are all in the junction box and I swapped it with another one.
    #32
  13. dtysdalx2

    dtysdalx2 Knowledge is horsepower

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    I'm not a fan of "swapping stuff until it works" at all.

    They make me do that at work and I... Well you know. :devildog
    #33
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  14. tntmo

    tntmo Oops, I did it again.

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    Yeah, I am not a fan either but when I have some parts and it's easy to swap I do it. I wish I had an ECU, it's starting to be my primary suspect.
    #34
  15. tntmo

    tntmo Oops, I did it again.

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    Yes, and I am getting 6VDC at the ECU when I turn on the key. It's about 8-9 VDC with the booster attached, which then starts the bike but it drops to six when I remove the booster and kill the engine at the kill switch. Then it starts no problem.
    #35
  16. dtysdalx2

    dtysdalx2 Knowledge is horsepower

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    Maybe try 9V at the ECU (BY pin?) from the ignition switch and see what happens. Jump it with a 9V battery.

    Resistors usually limit current and volts shouldn't drop too much. Who says you need 6V or more? Factory service manual?

    I like these mystery electrical problems too. :D Now I have to remember all that stuff again.

    I suspect it looks for LESS than battery voltage since hot wiring will make it 12V. :scratch

    https://www.ninjette.org/forums/showthread.php?t=270465
    #36
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  17. baloneyskin daddy

    baloneyskin daddy bikaholic

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    Just for the hell of it ,drive it to a big hill and see if it will drift start when this happens at least then you may be able to narrow it down a little or push it over the cliff.
    #37
  18. dtysdalx2

    dtysdalx2 Knowledge is horsepower

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    Did you buy an aftermarket ignition switch or a factory OEM switch? On some years of the Kawasaki bikes, they use a tamper proof ignition switch so you can't bypass the ignition to steal the bike. The aftermarket switches do not have the correct resistor in it so they will not work. You can often damage the igniter by using an aftermarket switch because it supplies the wrong voltage.

    You can do two things.
    1. Try and wire in a resistor and see if it will work. I am posting the only diagram I have for doing that. It isn't for your bike, but will show you that the wire to the igniter needs reduced voltage and the size of resistor to try. There is no factory information available because it is an anti-theft device.

    2. Order the factory switch.

    [​IMG]

    Stolen from the internet. :)
    #38
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  19. dtysdalx2

    dtysdalx2 Knowledge is horsepower

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    Moar...

    No need to re-invent the wheel. There's wiring-diagram at bottom of linked thread in post#5 above. Reverse-engineered from actual bikes and more accurate than factory FSM. Because FSM doesn't show resistor, it's security-feature built into ignition-switch.

    There's only TWO types of wires to worry about at ignition-switch.

    1. INPUT - brown wire coming in with power from battery
    2. OUTPUT - goes to various circuits like horns, lights, etc. ONE of these, is a GREY wire going to the ignition computer

    The way it works is the ignition computer compares voltage on GREY wire vs. BLACK/YELLOW wire directly connected to battery. If the voltages are the same, the bike's been hot-wired and it will refuse to start. So the resistor's presence is to signal that it's actually ignition switch that turned on bike.

    You've got intermittent problems, nothing to do with the resistor, that's an all/or nothing, black/white, yes/no binary indicator. Either the bike starts or it won't and the condition will be permanent, not random (resistors don't change resistance day-to-day). You've got loose wiring, shorts, or bad connectors somewhere. Pull out the voltmeter and get voltages at every wire, going into and out of every connector.

    Also get out hair-dryer and get the ignition computer hot. See if it stumbles then? There's been cases of overheated ones failing.
    #39
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  20. tntmo

    tntmo Oops, I did it again.

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    It has the factory ignition switch. The resistor is to prevent someone from just twisting wires together to steal the bike, it's supposed to reduce the voltage signal to the ECU to about 6 VDC. The resistor is working as advertised, I checked it with the multimeter and it reads 100 ohms resistance and it sends 6 VDC to the ECU. Which doesn't start the bike. With the booster, it's getting about 8-9 VDC, which starts the bike....but after it starts I can shut off the booster and kill switch, then start the bike again with 6VDC at the ECU.

    I think there is some short or bad connection somewhere, and the booster helps push voltage past it. I just need to locate it. It's either that or the ECU itself is malfunctioning but it would seem to me that it would either fail all the time, work all the time on the booster, but not work initially on the booster and then work fine off of it until the key is cycled.
    #40