Find the ballast resistor, and with key in "run" but engine off, check the voltage on the resistor. You want the highest reading, one will be near battery and one will be low, ONLY if the points are closed. If both are high, put your meter on the coil NEG terminal (distributor connection) and bump the engine until the reading goes low. Then check the highest side of the ballast and compare that reading to the battery. It should be within a few tenths of a volt.