The purpose for checking the wire from the negative coil terminal to the distributor is to see if the points are providing a ground to the coil primary winding. Attach the ohmmeter leads to the wire going fron the - terminal to the distributor, and to an engine ground like a valve cover bolt, carburetor linkage, etc. If the points are conducting, you will see a very low resistance. This MUST be done with the wire disconnected from the coil or you'll get a false reading. Points closed- - - - -low resistance. Points open- - - -very high resistance. Unless this is happening, you'll never get any spark, no matter how many parts you change. The points are the switch that turns the coil on and off, creating the spark.
If the primary winding is actualy open-circuited, you've got a bad coil- - - -a very rare failure. The normal resistance of a primary coil winding (+ to -) is about 2 to 3 ohms. If the ohmmeter is connected between the + terminal and the high-voltage tower that produces the spark, the resistance should be around 10,000 ohms. Good luck!
Jerry
