Mercathode Control Module; Mercathode Theory Of Operation - Mercury 6.2L MPI Manual

Section 4 - Maintenance

MerCathode Control Module

The MerCathode control module is mounted on the front of the engine. A decal near the control module is a quick reference to
identify the operation condition of the control module. Refer to MerCathode Theory of Operation for a thorough explanation
on the state of protection the MerCathode is providing and whether or not the system requires inspection by an authorized
Mercury MerCruiser dealer.
a
a

MerCathode Theory of Operation

The MerCathode system provides corrosion protection by impressing a reverse blocking current that stops the destructive flow
of galvanic currents. The MerCathode controller will regulate output to maintain 0.94 volts at the reference electrode.
A constant LED indicates that the system is operating correctly. A flashing LED indicates that a fault has occurred, or that an
abnormal condition exists.
IMPORTANT: When a boat or new drive is first put into service, the LED may initially indicate that the protective current is not
being supplied through the MerCathode anode. This condition is normal, and, in such cases, the LED may flash for a period.
The light from the LED will become steady after the boat is moored for a period of eight hours without operation.
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Standard cooling
a - MerCathode control module LED
55620
Closed cooling
a -

MerCathode control module

90-8M0128973 MAY 2017
eng