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:
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) also reading 11.75 volts as no current is now being drawn through the ballast to lower the voltage at the coil:
Cranking and running voltages to follow.