40 hp Johnson, starter solenoid will not work all the time, brand new solenoid will work one time and not the next, no clicking, I have voltage to the wire from the key and voltage to the other small terminal, and of course there is voltage at the positive battery cable on the solenoid but no voltage to the starter side of the solenoid. could I be getting low voltage from the key switch wire and therefore not enough voltage to kick the starter over? is the solenoid just an electricaly operated switch?