[Patrick L.]

With key on there should be voltage to the moveable point arm when it is open [high point on cam showing an air gap] . That indicates there are no problems such as opens or grounds in the primary circuit.

When points are closed there should be no voltage indicating that the stationary point contact is grounded.

With a 12v negative grd system, the coil primary wires will need to be reversed. The negative coil wire will be to end up going to the points.

You'll need to know what type coil you are using. Does it contain a resistor, it not, you'll need to and an external ballast. It'll either be a 1.5 ohm or 3.0 ohm coil. If its oil filled then it should be mounted with the secondary coil wire pointing to the sky.