Here is outboard boat motor wiring diagram for Mercury 402. Mercury 402 boat motor has 40 hp powers, electric start, and remote controls. In this black white wiring diagram, a connection form engine harness connect to starter motor, starter solenoid, choke solenoid, coil, rectifier, trigger plate, coil, and tilt stop switch. External harness connects to 12 volt battery, neutral start interlock switch, tachometer connector, key switch, and remote control. Here full mercury boat motor wiring diagram.