lancsamb wrote:as i understand the coil starts at 12 volts and then reduces
The coil usually runs through the ballast resistor which supplies it with a lower voltage, but during starting there is a bypass wire that runs from the starter solenoid and supplies the full voltage without resistance. As soon as you let go of the key and the starter stops (because the engine is running), the by-pass is disconnected and the lower voltage is present. With the load of the starter, this usually results in about 9-10v during starting, to give a bit of a boost.