Power Trim And Mercathode Overload Protection; Warning Horn Signals - Mercury TDI 3.0L Owner's Operation And Maintenance Manual

Section 1 - Getting to Know Your Power Package
Dual engine applications may have a single integral button to operate both sterndrives simultaneously or may have separate
buttons for each sterndrive.
Some controls also have a trailer button that trims the sterndrives to a position suitable for trailer purposes only.

Power Trim and MerCathode Overload Protection

If an electrical overload on the electrical system occurs, a fuse will open (blow). Find and correct the cause before replacing the
fuse.
NOTE: If you must operate the engine in an emergency, turn off and disconnect all accessories from the engine and
instrumentation wiring if you cannot find and correct the cause for the electrical overload or excessive current draw. Replace
the fuse. If the fuse burns out, the electrical overload has not been eliminated. Further checks must be made on the electrical
system. Contact your Mercury Diesel authorized repair facility.
1. The power trim system is protected from overload by a 110‑amp fuse and a 20‑amp in‑line fuse on the power trim pump.
a
2. There are several different Quicksilver MerCathode systems available. Each has a fuse connected to the positive (+)
terminal on the controller. If the fuse is open (blown), the system will not operate, resulting in a loss of corrosion protection.
Replace the fuse with one of the same amp rating.
a
c
b

Warning Horn Signals

When the key switch is turned to the on position, the horn will turn on for a moment as a test to indicate the horn is working.
There are two types of warning horns to alert the operator of an active problem within the engine's operating system.
1. Continuous six second beep: Indicates a critical engine condition. Depending on the condition, the Engine Guardian
system may engage and protect the engine by limiting power. You should return to port immediately and contact your
servicing dealer.
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b
a - MerCathode
b - Red/purple wire
c - Fuse
50534
a - 20‑amp in‑line fuse holder
b - 110‑amp fuse
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90-8M0145546 MAY 2018
eng