Alternator Voltage Regulator Removal And Installation; Over-Voltage Warning System; Aircraft Lighting System Troubleshooting - Cessna 177 SERIES Service Manual

Charging Systems Service /Parts Manual. show a discharge. Turn off both sections of the Master
Switch to recycle the over-voltage sensor. If the
16-43C. ALTERNATOR VOLTAGE REGULATOR. over-voltage condition was transient, the normal al-
BEGINNING WITH 17702673.
ternator charging will resume and no further action
is necessary. If the over-voltage trip-out recurs then
16-43D. DESCRIPTION. The regulator is solid state and a generating system malfunction has occurred such that
not repairable in the field The regulator is a remove and the electrical accessories must be operated from the
replace item. A bench adjustment procedure is outlined
aircraft battery only. Conservation of electrical energy
in the Cessna Alternator Charging Systems Service/
must be practiced until the flight can be terminated.
Parts Manual.
The over-voltage red warning light filament can be
tested by turning off the Alternator portion of the
16-44.
TROUBLE SHOOTING. For trouble shooting Master Switch and leaving the Battery portion turned
the voltage regulator, refer to paragraph 16-39.
on. This test does not induce an over-voltage condition
on the electrical system. On models prior to aircraft
16-45. REMOVAL AND INSTALLATION. (Refer to
serial 17701690, should nuisance trip-out occur caused
figure 16-5.)
by voltage spikes or transient voltage, a trip-out
a. Make sure that the master switch is off, or discon-
capacitor should be installed in the system in accordance
nect the negative lead from the battery.
with Cessna Single-engine Service Letter SE72-15, dated
b. Remove the connector plug from the regulator. April 21, 1972. After installation if the over-voltage
c. Remove two screws holding the regulator on the trip-out recurs then a generating system malfunction
firewall.
has occurred such that the electrical accessories must be
d. To replace the regulator, reverse the procedure.
operated from the aircraft battery only. Conservation
Be sure that the connections for grounding the alter-
of electrical energy must be practiced until the flight
nator, wiring shields and the base of the regulator can be terminated.
are clean and bright before assembly. Otherwise,
poor voltage regulation and/or excessive radio noise 16-48.
AIRCRAFT LIGHTING SYSTEM.
may result.
16-49.
DESCRIPTION. The aircraft lighting system
16-46. OVER-VOLTAGE WARNING SYSTEM. consists of landing and taxi lights, navigation lights,
flashing beacon light, anti-collision strobe lights,
16-47.
DESCRIPTION. Beginning with 1972 Models, dome light, instrument flood lights, courtesy lights,
an over-voltage warning system is incorporated in the control wheel map light, compass and radio dial lights.
aircraft. The over-voltage warning system consists On 1969 models & on, snap-in type rocker switches
of an over-voltage sensor switch and a red warning are introduced. These switches have a design feature
light labeled, "HIGH VOLTAGE", on the instrument
which permits them to snap into the panel from the
panel. When an over-voltage trip-off occurs the over- panel side and can subsequently be removed for easy
voltage sensor turns off the alternator system and
maintenance. These switches also feature spade type
the red warning light comes on. The ammeter will slip-on terminals.
16-50. TROUBLE SHOOTING-- AIRCRAFT LIGHTING SYSTEM.
TROUBLE PROBABLE CAUSE
REMEDY
LANDING AND TAXI LIGHTS Short circuit in wiring. 1. Inspect circuit breaker. If
OUT
circuit breaker is open, proceed
to step 2. If circuit breaker is
OK, proceed to step 3.
Defective wiring. 2. Test each circuit separately
until short is located. Repair
or replace wiring.
Defective switch. 3. Check voltage at lights with
master and landing and taxi light
switches ON. Should read bat-
tery voltage. Replace switch.
LANDING OR TAXI LIGHT
Lamp burned out. 1. Test lamp with ohmmeter or
OUT.
new lamp. Replace lamp.
Open circuit in wiring. 2. Test wiring for continuity.
Repair or replace wiring.
FLASHING BEACON DOES
Short circuit in wiring. 1. Inspect circuit breaker. If
NOT LIGHT.
circuit breaker is open, proceed
to step 2. If circuit breaker is
OK, proceed to step 3.
16-14 Change8