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Need help getting spark out of a 302...

Discussion in 'The Hokey Ass Message Board' started by str33tz, Aug 11, 2015.

  1. str33tz
    Joined: May 24, 2010
    Posts: 37

    str33tz
    Member
    from las vegas

    302 out of a 1975ish Granada.

    Long story short, car ran decent few months back. Sat for a bit, got some headers made for it, exhaust shop installed shorty accel plugs in it.

    Got it together enough after exhaust shop to fire it up. Had spark a few weeks back and had it running (barely) with a bit of misfiring. (Accel plugs)

    Checked Dizzy cap, looked decent, no burns and no cracks. Rotor looks decent.

    Today, new plugs(auto lite),new coil, no spark at all.

    With key to run I only have 2.5v coming out of ballast. With a hot 12v wire to coil I still get no crank. I don't have a buddy to help me crank n check voltages at the moment.

    It's my understanding the ballast resistor should pump out 6-9v. Should I hook up a 12v wire to coil from starter/ignition solenoid? If it gets 12v while starter cranks, shouldn't that theoretically provide extra juice to the dizzy to fire the car, then when key drops to run it stays powered off the ballast power(6-9v)?

    So where should Start to narrow down the culprit before I throw parts at it?

    How can I test/bypass ballast? What is necessary voltage coming out to coil?

    The car only had one wire hooked up to + on coil, which came from ballast. Does it need a 12v wire from starter terminal on starter solenoid for the extra voltage to fire the car up?

    How can I test my new coil? (O'reillys master pro 2-5195)

    Other then cracks/burn marks what do I need to be checking on dizzy/rotor?

    Any help is greatly appreciated. I'm sure it comes down to cap+rotor or ballast. Just would like to know for sure.
     
  2. partssaloon
    Joined: Jan 28, 2009
    Posts: 485

    partssaloon
    Member

    What's it in? what kind of distributor? Stock or aftermarket wire harness?
     
  3. str33tz
    Joined: May 24, 2010
    Posts: 37

    str33tz
    Member
    from las vegas

    1960 falcon. Points dizzy. Haywire harness.

    The original ballast which appears extremely old, had a burnt wire/contact inside and was split. Im going to get a ballast.

    If I'm running a master pro 2-5195 coil, which i believe is 12v and does require a ballast resistor, what kind of ballast do I want to run with this coil? I believe coil is 1.5 primary resistance.
     
  4. You want a ballast resistor of about 1.5-2 ohm resistance. The main trick will be finding one that will take the needed current flow, in this case about 5 amps. Get a wire-wound ceramic resistor rated for 100 watts and you'll be good to go. And yes, you want a wire from the 'S' terminal on the starter solenoid to the coil. You don't have to connect it to the coil, you can connect it on the coil side of the resistor.
     

  5. F&J
    Joined: Apr 5, 2007
    Posts: 13,222

    F&J
    Member

    You can test fire the engine with the ballast jumped. Put 12v to the plus side of coil to see if it has spark when trying to start the motor.

    Back to voltage readings at ballast: A ballast will show 12 in and 12 out if the points are open. It will show resistance (lower volts) only if the points are closed, and IF the points are making good contact.


    The solenoid has an "I" terminal that sends a full voltage to the coil, only when the starter is cranking. Once it starts, you then are running through the ballast.

    a test to see if points are working OK: Put a test light from the minus side of coil, to ground. When you crank the starter, the light should blink on and off as the points open/close each time. Not just slightly dimmer, but definately off and on.

    If the light stays on when cranking, the points are not making a good contact.

    if the light stays out all the time, it could be a shorted condenser, or a shorted wire from the minus coil wire into the distributor...or even a shorted coil in very rare instances.
    .
     
  6. Splinter
    Joined: May 14, 2005
    Posts: 1,112

    Splinter
    Member

    You must run a ballast with points-too much current otherwise, and you'll fry your points. It's OK for startup, but not long term. Check condenser and points-most likely culprit.......
     
  7. F&J
    Joined: Apr 5, 2007
    Posts: 13,222

    F&J
    Member

    did you type the wrong letter? If he puts a wire from coil plus side, to S on solenoid, the starter will start cranking when the key is turned to the "on" position.
     
  8. Yep, meant 'I'....
     
  9. OK, to start with a 1960 Ford Falcon should Not have a ballast resistor - they had a resistor wire under the dash that knocked the voltage down appropriately. If you bought a new wiring harness was it universal or was it specific to the Falcon?
    Second, YES you need a wire from the solenoid to the coil to start the car. The one from the key switch does not provide power during cranking so the only spark it sees it the instant you quit cranking before you shut the key back to off.
     
  10. Mike51Merc
    Joined: Dec 5, 2008
    Posts: 3,855

    Mike51Merc
    Member

    First things first, get the engine to run by itself and then worry about the car's wiring/harness/resistor, etc. later.
    You said you already tried a hot wire directly from battery to coil---- if the car didn't run when hot wired, then you have a problem somewhere between the coil and the spark plugs. Could be a short in the distributor, bad condenser, bad point setting, wrong timing, bad wires, bad coil.
     
    Last edited: Aug 14, 2015
  11. Don't forget to clean the points!
     

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