1995 Johnson/Evinrude Outboards 9.9, 15 four-stroke Service Manual, Page 191Get this manual
High Voltage
In some conditions, the key switch may be shorting (some leakage) to the other terminals in the key switch, but will not show up with test light or an ohmmeterThis condition may be found by using condenser tester (leakage test) where voltage of approximately 500 volts is applied to the key switch terminals
With all leads disconnected and the key switch in the "OFF" position, connect the black lead of the tester to one of the "M" terminals of the key switch1Attach the red lead of the test to the "B" terminal and apply leakage test2Repeattest by moving the red lead to each ofthe terminals and applying the leakage testThe meter will indicate if leakage is present3When applying test to other "M" terminal, turn key to the "ON" position