AUDIO SYSTEM - Specifications 8-193
NOISE SOURCES
Source of Electrical System Noise
Ignition system
(1) Spark plug
(2) High tension cable
(3) Distributor Power generation system
(1) Ripple at contact between alternator
armature and carbon brush
(2) Spark from voltage regulator contact
!
Other electrical device
(1) Armature of wiper, blower and other
motors.
(2) Starter and switch when starting engine
(3) Spark from changeover switch
(4) Horn
(5) Contact of turn signal
(6) Loose contact of wiring harness
(7) Static electricity generated by tire or
generator drive-belt
(8) Voltage stability unit for instrument
Noise Sourse of Vehicle Equipment
Kind of noise
Whistling sound Equipment
Alternator Symptom of noise generation
Noise increases when accelerator pedal is
depressed and it subsides soon after engine
is stopped.
Scratching sound
Water temperature gauge unit Noise is produced while engine is running
and it persists for a while after engine
shutdown.
Fuel gauge unit Noise is produced at sudden acceleration,
driving on rough road or when ignition key is
placed to ON.
Jarring
Wish-wash,
wish-wash
Buzz, click Oil pressure switch
Flasher relay
Horn
Wiper motor
Washer motor Noise is produced with engine operation
and no noise is made when engine is idling.
Noise is produced with operation of turn
signal light
Noise is made when horn button is pressed
or released.
Whinning Noise is generated with the wiper speed.
Noise is made when washer is operated.
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AUDIO SYSTEM - Noise Suppression 8-201
NOISE SUPPRESSION CHART
Symptom
Unusual noise related to
engine speed. ’ Remedy
Securely ground the engine, frame and/or body and engine
hood.
- Ground wire
16E71C
“Clatter” noise related to the
Turn signals
flashing of turn signal lights Connect a 0.5 FF noise-suppression capacitor to the 6 terminal
of the flasher unit.
Abnormal noise when
the horn is operated. Horn ?L - 0.5pF noise suppression
capacitor
16E71:
1. Connect a 0.5 FF noise-suppression capacitor to the + B
terminal of the horn.
2. For an FM radio, connect an LC filter to the horn terminals.
Noise when the wind-
shield washer oprates. Washer motor Horn LC filter
16E71:
1. Connect a 0.5 PF noise-suppression capacitor between
the terminal of the washer motor and the power source
wire.
2. For an FM radio, connect an LC filter between the terminal
of the washer motor and the power source wire.
Unusual noise when the
engine is started. Water tempera-
ture gauge unit Connect a 0.1 p,F noise-suppression capacitor to the terminal o
the water temperature gauge unit.
0.1 PF noise suppression
capacrtor
1 STB Revision
