2004 SR Johnson 2-stroke 40, 50HP Service Manual, Page 93Get this manual
ELECTRICAL MWS CIRCUIT TESTS
Emergency Stop Switch Test
This switch can be incorporated into the key switch or achieved through separate switchEither style effectively connects the "M" terminals of the key switchThe emergency stop switch function grounds the stop circuit wire (blackyellow) when the lanyard clip is removed One "M" terminal is the ground wire (black) and one "M" terminal is the stop circuit wire (blackyellow)
MWS CIRCUIT TESTS
Test the condition of the boat modular wiring system (MWS) using Tester, PIN 437274Power to the tester is supplied by: 110 VAC adapter supplied with the tester; or Two internalrechargeable batteriesTo recharge batteries, move tester power switch to OFF and plug in the A.CadapterThe circuitry in the tester is protected from overload by circuit breaker1Lanyard and clip assembly 2Emergency stop switch, separate from key switch 3Stop circuit wire (blackyelow) 4Ground wire (black)