[rotorwrench]

The Electrolock design controls the ground pathway from the breaker points to the coil so it only has to have continuity at each end when the switch is in the on or pushed in position. The off position with the button popped out should have no continuity. An internal short test can be done by testing from either terminal to the body of the housing while it is switched on. It should have no continuity from the ground circuit to the housing. This is a good bench check with the assembly on the bench being tested with a multi meter set to check resistance or continuity.

With the assembly installed to the distributor, the breaker points are in play. With breaker points open, there will be no continuity to ground with switch on. With points closed, there should be continuity to ground.