Overload Protection-Port Side Power Distribution Box - Mercury 4.2 Diesel Operation & Maintenance Manual

After finding and correcting the cause of the overload, reset the circuit breaker by pressing the reset button.
Reference Circuit breaker rating
a
b
c
d
e
f
Overload Protection—Port Side Power Distribution Box
If an electrical overload occurs, a fuse will open (blow) or a circuit breaker will open (trip). Find and correct the cause of the
electrical overload before replacing the fuse or resetting the circuit breaker.
NOTE: In an emergency, when the engine must be operated and the cause of the high current draw cannot be located and
corrected, turn off or disconnect all the accessories connected to the engine and instrumentation wiring. The circuit breaker
should automatically reset. If the breaker remains open, the electrical overload has not been eliminated. Further checks must
be made on the electrical system. Contact your Mercury Diesel authorized repair facility.
Circuit breakers provide protection for the engine electrical system as indicated. The circuit breaker panel is located within a
power distribution box mounted on the engine control module.
After finding and correcting the cause of the overload, connect the starting battery and turn the ignition switch to the run
position. The circuit breaker should automatically reset. If a circuit breaker fails to reset, contact your Mercury Diesel authorized
repair facility
90-8M0113988 DECEMBER 2015
eng
c
b
a
Circuit breakers viewed from the port side of the engine
20 A Key unswitched power to helm
10 A
10 A
15 A
15 A
5 A Power—diagnostic connector
Port Side Power Distribution Box
Section 1 - Getting to Know Your Power Package
Protection
Switched power to ECM
Key switch to ECM
Switched power to ECM
ECM switched power to SIM
d
e
f
23245
Location on fuse panel
Lower left
Upper left
Middle left
Middle right
Upper right
Lower right
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