ENGINE
ELECTRICAL
SYSTEM
103
2
Check
the
lead
Wires
of
the
armature
coil
Includmg
the
neutral
wire
for
ground
as
shown
In
Figure
42
HIgh
reSIStance
no
current
flow
indicates
gqod
condItion
If
not
the
stator
must
be
replaced
DIODE
INSPECTION
The
diodes
can
be
inspected
through
the
use
of
a
lamp
and
battery
or
with
a
tester
The
lamp
and
battery
test
can
be
made
Without
disassembl
ing
the
alternator
wh1le
the
tester
should
be
used
when
the
dIodes
are
dIrectly
acceSSIble
1
Positive
Dwde
Test
Connect
the
battery
negative
terrmnal
WIth
the
connector
A
terrmnal
WhIte
and
the
battery
pOSItIve
terminal
With
the
connector
N
terrmnal
yellow
as
shown
m
Figure
43
The
lamp
m
the
circuit
should
hght
@
Reverse
the
connection
as
shown
m
Figure
44
If
the
lamp
does
not
hght
the
pOSItIve
diodes
are
satisfactory
If
the
lamp
does
light
one
or
all
of
the
pOSItIve
dIodes
are
defective
and
must
be
replaced
@
Qg
2
Negative
DIOde
Test
Connect
the
battery
negatIve
termmal
to
the
connector
N
terrmnal
yellow
and
the
battery
pOSItIve
termInal
to
the
connector
E
termmal
black
The
lamp
m
the
CIrcUit
should
lIght
Reverse
the
connectIons
If
the
lamp
does
not
lIght
the
nega1
ve
dIodes
are
satlsfactory
If
the
lamp
does
lIght
one
or
all
I
of
the
negatIve
dIodes
are
defectIve
and
must
be
replaced
To
test
the
indiVIdual
dIodes
With
a
tester
proceed
as
follows
1
There
are
two
kInds
of
diodes
as
shown
m
Figure
45
Check
dlOd
reSIstance
usmg
a
tester
In
both
dIrectIons
as
jl
own
in
Figure
46
f
Current
flow
@
Current
flow
re
ack
flgUre
e
terminal
r
Positive
diode
Negative
diode
@
122
CHAPTER
TEN
1
Start
the
engIne
and
bnng
It
up
to
normal
operatIng
temperature
2
Inspect
all
hoses
and
connectIons
for
leaks
and
detenoratIon
Shut
off
the
engme
Replace
any
defectIve
hoses
3
Remove
the
hose
attached
to
the
check
valve
4
VIsually
Inspect
the
posItIon
of
the
valve
plate
InsIde
the
valve
body
See
Figure
10
It
should
be
lIghtly
posItIoned
agaInst
the
valve
seat
away
from
the
aIr
dlstnbutor
manifold
5
Insert
a
probe
Into
the
valve
connectIon
on
the
check
valve
Depress
the
valve
plate
It
should
return
freely
agaInst
the
valve
seat
when
released
6
Leave
the
hose
dISconnected
and
start
the
engme
7
Slowly
Increase
engine
speed
to
1
500
rpm
Watch
for
exhaust
gas
leakage
at
the
check
valve
There
should
not
be
any
The
valve
may
flutter
or
VIbrate
at
Idle
speeds
ThIS
IS
normal
Replace
the
valve
u
defecuve
Anti
Backfire
Valve
1
Start
the
engme
and
bnng
to
operating
temperature
2
Inspect
all
hoses
and
hose
connectIons
for
leaks
and
detenoratIon
Replace
as
required
3
DIsconnect
the
hose
at
the
antI
backfire
valve
leading
to
the
Intake
manuold
Insert
a
plug
ill
the
hose
and
fasten
securely
4
Open
and
close
the
throttle
valve
rapidly
See
Figure
11
Place
a
finger
over
the
valve
outlet
to
the
m
take
manuold
If
arr
flow
IS
felt
for
one
to
two
seconds
the
valve
IS
functIonIng
properly
If
there
s
no
aIr
or
If
the
flow
is
felt
for
more
than
two
seconds
the
valve
IS
defectIve
and
must
be
replaced
5
Connect
the
alr
hose
to
the
mtake
manuold
after
remOVIng
the
plug
6
DIsconnect
the
aIr
mlet
hose
from
the
air
pump
at
the
antI
backfire
valve
If
the
engine
Idle
speed
changes
excessIvely
the
valve
is
de
fectIve
and
must
be
replaced
Air
Pump
1
Check
the
atr
InjectIon
pump
belt
tension
DeflectIon
of
the
belt
should
be
0
5
In
when
pushed
In
by
thumb
pressure
Adjust
belt
u
necessary
2
Operate
the
engme
untIl
normal
temperature
IS
reached
3
Inspect
all
hoses
hose
connectIons
and
the
arr
gallery
for
SIgnS
of
leaks
or
detenoratIon
Replace
as
required
4
DIsconnect
the
air
supply
hose
at
the
check
valve
5
Insert
the
open
pipe
end
of
a
pressure
test
gauge
adapter
Into
the
air
supply
hose
See
Fig
ure
12
Clamp
the
adapter
firmly
to
the
hose
Install
the
pressure
test
gauge
to
the
adapter
PosItIon
the
adapter
and
test
gauge
so
that
the
alr
blast
emitted
through
the
dnlled
pipe
plug
Will
be
harmlessly
dislppated
6
Install
a
tachometer
on
the
engme
WIth
the
engIne
speed
set
to
1
500
rpm
observe
the
pres
sure
readmg
AIr
pressure
should
be
0
47
m
Hg
16mm
Hg
