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Can a failing coil cause points to fail?

Discussion in 'Early CJ5 and CJ6 Tech' started by ZipTy, Jan 19, 2006.

  1. Jan 19, 2006
    ZipTy

    ZipTy Member

    Evansville, IN
    Joined:
    Sep 22, 2005
    Messages:
    84
    Replaced points, still not running. Even though I was getting some power to the distributor I was not getting an arc from the top of the coil when I would crank the engine. Any suggestions?
     
  2. Jan 19, 2006
    sparky

    sparky Sandgroper Staff Member Founder

    Perth, WA
    Joined:
    Sep 20, 2002
    Messages:
    9,221
    First: Points gapped correctly, not grounding out and dwell set correctly?
    Spark across the points?
     
  3. Jan 19, 2006
    green71jeep

    green71jeep work in progress

    Riegelsville Pa
    Joined:
    Sep 6, 2005
    Messages:
    144
    Bad ballast resister?
    Bad coil wire ?
     
  4. Jan 19, 2006
    lynn

    lynn Time machine / Early CJ5 HR Rep Staff Member

    Huntingdon PA
    Joined:
    Sep 20, 2002
    Messages:
    3,437
    Replace condensor?

    Here's some info in a reply to a similar question on type2.com:
    ************************************************
    Question: "I've got no spark at my coil and can't figure out why. I have checked everything I can think of. I have replaced the coil and condenser with new ones. I swapped out the distributor. I ran a hot wire from the battery to the coil to eliminate the ignition switch as a possibility."

    Reply:
    My guess would be a grounded (or open) set of points. (Two piece points? did you forget the fibre washer under the spring?) First check for power to the coil. If you have 12v there, then manually open the points and check for spark from the coil. If no spark, remove the wire from the points and manually "spark" it to ground. If spark, then problem is bad points or condensor. If no spark, then the problem is coil or the wire to the points. To check the coil, disconnect the wires from it and take your multimeter (You do have a multimeter, don't you...) and check the resistance between the 1 and the 15 terminals. I don't remember how much it should be, but it will be a bunch. 20k ohms? It shouldn't be open or shorted. If it is, replace it. To check the points, rotate the engine 'til the points are open and check that the fixed point has 0 resistance to ground and that the movable point has infinate resistance to ground. Bad condensor? The only way to check that is to replace it with a "known" good one. (A known good one could be the one that you took out of the bus the last time you tuned it and it was runnung.) The Kettering ignition is really pretty simple to troubleshoot.

    To quote L.J.K. Setright:

    "...a battery to supply electricity, a coil to transform that low voltage supply to a much higher electrical pressure, with the assistance of a contact breaker which triggers it to produce a very high voltage pulse, which is led , via a distributor, to the appropriate spark plug where the pulse comes across the gap between the electrodes, igniting the charge in the process. The only other essential is a condensor, wired to the contact breaker to prevent excessive arcing or sparking across the points as they open to trigger the pulse from the coil..."
    *************************
     
  5. Jan 19, 2006
    ZipTy

    ZipTy Member

    Evansville, IN
    Joined:
    Sep 22, 2005
    Messages:
    84
    Gapped the point to .020 and got it running pretty strong. Pertronix here I come.
     
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