Four winns Vista 328 Owner's Manual page 63

Disconnect the battery before working on elec-
trical or ignition system to prevent electrical
shock and accidental ignition.
B. Electrical Wiring Maintenance
Periodically, inspect all wiring for nicks, chaffing, embrittle-
ment, improper support, etc. Examine the shore power
cord closely for insulation cracks and corrosion in the
electrical devices. Spraying the receptacles and electri-
cal connections with an electrical connection cleaner will
reduce corrosion and improve electrical continuity.
DO NOT allow corrosion to build up on connec-
tions. Shorts or ground faults can result.
The entire 120 (220) volt circuitry, especially the shore
power cord, should be seasonally tested for proper conti-
nuity by an experienced marine electrician. This will help
detect any short, open wire, or ground fault. Also, check
the polarity indicator system for proper operation.
120 (220) volt AC electrical power can be danger-
ous. DO NOT attempt to service a system un-
less you are familiar with, and experienced in,
performing such service.
H - 9 STRAY CURRENT CORROSION
A. General
Electrically induced underwater corrosion occasionally
affects boats and their related components. This is re-
ferred to as “Stray Current Corrosion” and appears as
surface pitting or deterioration. Stray current corrosion is
the decomposition of chemical compounds by electric
current.
Stray current corrosion can be caused by surrounding
boats; an improperly wired battery/charger installation or
other boats that are in close proximity which have electri-
cal power leakages. Stern drive units are especially vul-
nerable to stray current corrosion.
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Periodically inspect the engine components to determine
if corrosion damage exists. If stray current corrosion
damage is found, determine and correct the cause of the
stray current to prevent further damage. Consult an experi-
enced marine electrician or contact your Four Winns
dealer for assistance.
The use of some shore power battery chargers, while the
boat is in the water and the battery is connected to the
system, can cause stray current corrosion. Have an ex-
perienced marine electrician review any battery charger
installation to ensure a stray current corrosion problem
will not develop. An improper battery connection is a
common cause of stray current corrosion.
NOTICE
Use only a battery charger designed to meet U.S.
Coast Guard regulations for external ignition pro-
tection.
Corrosion is usually more prevalent in polluted or salt water
than in clean water. It is also more likely to occur when
dockage is in an area with steel piers, large metal boats,
or where shore power is in use.
B. Galvanic Corrosion
Galvanic corrosion results from a potential electrical dif-
ference existing between dissimilar metals immersed in
a conductive solution (e.g., salt water). If these metals
touch or are otherwise electrically connected, this poten-
tial difference produces an electron flow between them.
The attack on the more active metal is usually increased
and the attack on the less active metal is decreased, as
compared to when these metals are not touching.
C. Corrosion Prevention
Anticorrosion anodes are attached to the bottom of the
gimbal housing to prevent corrosion to your stern drive
and underwater parts. These anodes will be slowly eroded
away by galvanic action and require periodic inspection.
Please refer to the section on “Anti-Corrosion Anodes” in
your engine manufacturer’s manual for additional infor-
mation.
Section H
Page 8