Ignition Coil Volts

Note that although in theory all meters should give the same readings on a given circuit in my experience both digital and analogue can vary.

Chrome Bumper   Rubber Bumper

Chrome bumper:

Points closed - left meter on the coil +ve (SW) switched to its 'VOLTS LOW' setting (0-13v scale) and showing 11.5v, right meter on the coil -ve (CB) switched to its 3v setting showing 0.65v:

Points open - left meter now showing 12.5 volts as the coil is no longer drawing current from the battery, right meter switched to its 30v setting (same 0-3v scale) showing 12.2 volts:

Rubber bumper:

Points closed - left meter on the coil +ve, 'LOW VOLTS' setting (0-13v scale), reading 5.75 volts as the battery voltage is being shared between ballast resistance and coil. Right meter on the coil -ve, 3v setting, reading just under 0.6v:

Points open - left meter now reading 12.25 volts, right meter switched to its 30v setting (same 0-3v scale) reading 11.75 volts as no current is now being drawn through the ballast to lower the voltage at the coil:

Variable dwell electronic ignition systems will give the same as the 'points' open readings as they don't pass a current through the coil until you start cranking.

Cranking and running voltages to follow.