Mitsubishi Pajero Pinin 1999, Workshop Manual

Page: 779 / 919

CHASSIS ELECTRICAL ±
Radio and Tape Player
Earth
cable
Fig. 1
54A-52
A-4 There is noise when starting the engine.
Noise type
Sounds are in
parentheses ( ).
Conditions Cause Remedy
FM/MW/LW:
Ignition
noise
(Popping, snap-
ping, cracking,
buzzing)
D
Increasing the engine speed
causing the popping sound to
speed
up, and volume
decreases.
D
Disappears when the ignition
switch is turned to ACC.
D
Mainly due to the spark
plugs.
D
Due to the engine noise.
D
Check or replace the
earth cable. (Refer to
Fig. 1 on P.54A-59.)
D
Check or replace the
noise capacitor.
Other electrical
components ± Noise may appear as electri-
cal components become old-
er. Repair or replace electrical
components.
Static electricity
(Cracking, crin-
kling)
D
Disappears when the vehicle
is completely stopped.
D
Severe when the clutch is
engaged.
Occurs when parts or wiring
move for some reason and
contact metal parts of the
body. Return parts or wiring to their
proper position.
D
Various noises are produced
depending on the body part of
the vehicle. Due to detachment from the
body of the front hood,
bumpers, exhaust pipe and
muffler, suspension, etc. Tighten the mounting bolts
securely. Cases where the
problem is not eliminated by
a single response to one
area are common, due to
several body parts being
imperfectly earthed.
Caution
1.
Connecting a high tension cable to the noise
filter may destroy the noise filter and should
never be done.
2. Check that there is no external noise. Since
failure caused by this may result in
misdiagnosis due to inability to identify the
noise source, this operation must be
performed.
3. Noise prevention should be performed by
suppressing strong sources of noise step
by step.
NOTE
1.
Capacitor
The capacitor does not pass D.C. current, but
as the number of waves increases when it
passes A.C. current, impedance (resistance
against A.C.) decreases, and current flow is
facilitated. A noise suppressing condenser
which takes advantage of this property is
inserted between the power line for the noise
source and the earth. This suppresses noise
by earthing the noise component (A.C. or pulse
signal) to the body of the vehicle.
2. Coil
The coil passes D.C. current, but impedance
rises as the number of waves increases relative
to the A.C. current. A noise suppressing coil
which takes advantage of this property is
inserted into the power line for the noise source,
and works by preventing the noise component
from flowing or radiating out of the line.