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ELECTRICAL
SYSTEMS
GENERATING SYSTEM
10-27
Figure
10-
1 8-Fan
Bel t
Adjustm
ent
LOOSEN LOWER AND UPPER
GENERATOR
CLAMP BOlTS
SHOWN
AT
"
A"
"
B" AND
"
C"
A SLIGHT AMOUNT
2ND ADJUST FAN BELT TENSION
TO V, INCH AS SHOWN
TIGHTEN LOWER CLAMP BOLT
"B" AND
RECHECK
TENS
ION
TIG HTEN CLAMP BOlTS
"
A"
FRONT
AND REAR AND "C
"
tha
t
pull
ey is free,
then
check
pull
ey for
tight-
n
ess
and check
generator bearing s
fo
r
fr
ee-
ness
of rotation and
exce
ssive side play.
Tight
or
ex
cessively
w
orn
bearings
should
be
cleaned
0/'
re
placed
6.
Inspect
and manually check all wiring
connections
at
generator,
r
egulator,
charge in-
dicator, and cranking motor solenoid switch
to make
certain
that
connections are
clean and
tight.
Clean a
ny
loose connections before
tight-
ening, to insure
good
contact. In
sp ect
wiring
for
broken
insulation,
broken strands,
and
loose terminals. Make
any
cor r ect ions nec
es-
sary to elim inat e excessive r
esistance.
b
. Testing
Generator Wiring
Circ
uit and
Generator
Output
After th
e inspecti on given above,
it is ad-
visable to t
est the
generator wiring circuit for
excessive r
esistance,
and to
test
the
generator
to make
certain
it has
proper
output.
1.
Disconnect
wire
from ge
nerator
r
egu-
lator
t
er minal
marked
"BAT" and connect an
ammeter in
series
with
this
t
ermin al and the
di
sconnect ed wire.
2.
Connect j
umpe r wi
r e between
r
egulator
terminal marked "
F " and base
plate
of r
egu-
lator so that
current
and
voltage
r
egulators
ca nnot
operate.
3.
Start engine and with all
electrical
units
turned
off, slowly
increase
sp
eed
until
ammeter
registers 20
amperes.
Quickly
ch
eck
voltage
across battery posts and also
between
gener-
ator "A"
terminal
and
ground.
If
generator
4.
If
commutator
and
brushes
are in good
condition but
dirty,
they can be cleaned with-
out removal of generator. Clean off any grease
with a cloth soaked with carbon
tetrachloride
or other
non-inflammable
sol
vent.
While
engine
is
running, polish commuta tor wit h
a
br ush
seating
stone
or with a strip of
2/0
sandpaper
placed
over a wood
en
block
having
a smooth
square
end.
See fig ur e
10-17.
Neuer us
e
em ery
cloth,
because
it wi
ll
ca
use arcing, burning
and
rapid
wear
of commutator and
brushes.
After
clea ning
commutator
blow
out
all dust from
g
en erator .
5.
Check
fa
n
belt fo
r conditi on
a
nd
proper
tension (fig
.
10-18),
and
mak e certain
that all
g
en erator
mounting
bracket
and brace bolts
are
tight. A loose fan
belt
will permit
belt slip-
page,
r
esulting
in rapid
belt wear
and low
or
erratic
generator
output.
An excessively tight
belt
will
cause
r
a pid
belt
wear and rapid wear
of
generator
a
nd
water
pu
mp bearings.
NOTE:
If
belt requires
adjustment,
first loosen belt so
Fig ure
10-17 -Cleaning Ge ner ator
Commutato r
3. Check condition of brushes; make
sure
they
are not binding in hold
ers
and that they
are
r
esting
on the commutator with suffici
ent
t
ension
to
give
good, firm contact. Brush leads
and screws must
be
tight.
If
the brushes
are
worn down to
one-half
their original lengt h
,
compared with
new
brushes, the
generator
must be removed for installation of n
ew
brushes. CAUTION:
When
ins pecting
bru sh es
do not pull th
em
out of hold
ers again st
spr ing
tension
by pull
ing
on
bru sh leads. This
may
loosen
th
e leads
in
brushes,
causing excessive
r
esistance , heating
and
open circuit s
to
de-
ve
lop.
Do not snap brush
arms
down on
brushes
as this may chip or crack th
em.
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