1983 Yamaha 30EN Outboards Service Manual, Page 151Get this manual
Inspection and repair Remote Control Box: Thoroughly clean the removed parts with suitable cleaning solvent and check for cracks, wear or other defectsReplace as requiredElectrical Parts: 1Main switch To check the main switch, tester is necessaryOnly when the main switch is in anyone of these positions should be continuityIf continuity exists when the main switch is in other positions, it is faultyaMain switch is in OFF WhiteBlack Continuity