1978 Johnson 175, 200, 235 HP Outboard Service Manual, Page 145Get this manual
KEY SWITCH CHECK (With continuity light or ohmmeter)
1Disconnect battery leads+BAT
2With key switch in "OFF" pOSition, connect continuity light or meter leads between key switch "BATT" and "A" terminalsLight or meter should not show continuity (open circuit)OFF
3Turn key switch toON" pOSitionmeter should show continuity
Light or
4Turn key switch to "START" positionor meter should still show continuity
5With key held in "START" position, transfer lead from "A" terminal to "S" terminalLight or meter should still show continuitySTART