There's a quick check for dirty points. Connect a test light between the distributor primary terminal at the coil and ground. As the points open and close, the light should flash on and off. Dirty points that aren't conducting will make the light stay on all the time. A short on the distributor side of the coil, grounded primary wire or condenser lead, etc. will keep the light off, points open or closed. Either way, the result will be no spark.
Jerry
