2000 Fat Boy...no spark

Discussion in 'Electrical' started by ritz, May 23, 2010.

  1. ritz

    ritz Member

    Evening all - I'd appreciate some much needed guidance with diagnosing a 'no spark' issue I'm having with my bike. The engine cranks, fuel is present but no spark to either plug. Up to this point the bike had been progressively getting worse with the daily initial startup...10-15 seconds of cranking before it kicked over.

    Here are the tests and results so far:

    1) battery kicking out 13.16 V
    2) 11.73 V making it to Terminal-B of the coil connector
    3) resistence of front & rear plug wires (6.62K & 2.99K resp.) within factory spec (front: 4.75K-11.23K & rear: 1.812K-4.375K)
    4) resistence of coil primary circuit is 1 ohm (factory: .5-.7)
    5) resistence of coil 2ndry circuit is 5.86K (factory: 5.5K-7.5K)
    6) test lamp on Terminal-A and -B of coil connector, with engine cranking gives NO light

    I'm thinking that my next step would be investigating the crank position sensor but I do not have the tool (i.e., breakout box) to properly diagnose.

    Am I missing something in my troubleshooting methods?

    Thank you.
  2. Hoople

    Hoople Account Removed

    If the crank position sensor is 2 wire, you can get away without a breakout box. Disconnect it from the wiring harness. Remove both spark plugs. Ground both spark plug wires to frame ground. Place an AC voltmeter across the crank sensor. Polarity is not important. Place the volt meter in a non-auto ranging 20 AC volt scale. Crank engine. What is your reading. Anything above 3 would be great.

    Also pull the sensor and clean it.
  3. ritz

    ritz Member

    Great news...the problem ended up being the crank position sensor. I'm up an running in preparation for Rolling Thunder. As a side note; In celebration of Memorial Day, let us not forget and honor those men and women who have made the ultimate sacrifice protecting our great Nation.