There is 12 volts coming in on red battery cable.
12 volts at purple wire in on position but just under 9 in start mode.
yellow striped wire has just under 9 volts in start position.
yes I am measuring from positive side of coil to a ground, not neg. side of coil
clean at the battery terminals
clean where the battery cables connect to the motor
clean where the main system ground is, usually stbd side motor mount bolt
clean where the canon plug goes together
clean on the terminals at the ign switch.