Aircraft Lighting System - Cessna 1969-1976 172 Series Service Manual

16-49. AIRCRAFT LIGHTING SYSTEM. anti-collision strobe lights, flashing beacon light,
16-50. DESCRIPTION. The a i r c r a f t lighting system light, control wheel map light, compass and radio
consists of landing and
taxi lights, navigation lights,
dome, instrument flood lights and courtesy light, map
dial lights.
Lamp burned out.
Open circuit in wiring.
Short circuit in wiring.
Defective wiring.
Lamp burned out.
16-51. TROUBLE SHOOTING,
1. Test lamp with ohmmeter o r
new lamp. Replace lamp.
2. Test wiring f o r continuity.
Repair
or replace wiring.
1. Inspect circuit breaker. If
circuit breaker
is
open, proceed
to step 2. If circuit breaker is
O.K. proceed to step 3.
2. Test circuit until short is lo-
cated. Repair or replace wiring.
3. Test lamp with ohmmeter o r
a new lamp. Replace lamp. If
lamp is good, proceed t o step 4.
I
TROUBLE
Defective flasher.
Short circuit in wiring.
LANDING AND TAXI LIGHT(S)
OUT.
1. Install new flasher.
1, Inspect circuit breaker. I f
circuit breaker is open, proceed
to step 2. I f circuit breaker is
0. K. proceed to step 3.
LANDING AND/OR TAXI
LIGHT OUT.
FLASHING BEACON DOES
NOT LIGHT.
FLASHING BEACON
CONSTANTLY LIT.
I
1
ALL NAV LIGHTS OUT.
I
PROBABLE CAUSE
I
REMEDY
Short circuit in wiring.
Defective wiring.
~~~~~
1. Inspect circuit breaker. I f
circuit breaker is open, proceed
to step 2. If circuit breaker is
O.K. proceed to step 3.
2. Test each circuit separately
until short is located. Repair
or replace wiring.
Defective switch.
3. Check voltage
at
lights with
m a s t e r and landing and taxi light
switches ON. Should read bat-
t e r y voltage. Replace switch.
Open circuit in wiring.
Defective switch.
Defective flasher.
4. T e s t circuit from lamp to
flasher for continuity. If no
continuity is present, repair o r
replace wiring. If continuity is
present, proceed to step 5.
5. Check voltage at flasher with
master and beacon switch on.
Should re ad battery voltage.
Replace switch. If voltage is
present, proceed to step 6.
6. Install new flasher.
Change 1 16-15