1987 Johnson/Evinrude CU Outboards 35A thru 55 Service Manual, Page 260Get this manual
Key Switch Check, 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 terminalsWith 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 apply leakage test
of the tester to the "8" terminal and
2Repeat test by moving the red lead to each of the 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
Start Switch Ohmmeter CheckTiller Electric Models
Disconnect the two switch leads from the starter solenoid1Set an ohmmeter to high ohms scaleAttach one ohmmeter lead to switch yellowred lead and the other ohmmeter lead to switch red leadDepress switch2Ohmmeter should show very low reading (zero) when switch is depressed and very high reading (00) when switch is releasedElectric start modelsTo replace start switch, remove two wires from start switch to starter solenoidRemove nut on start switch and remove assemblyWhen installing, refer to Wiring Diagram for correct wiring