Operation; Fuel Gauge - Datsun BLUEBlRD P 410 Series Service Manual

So be
sure
to
clean the
aIr vent
of the cap
If you should lose the cap and substItute
a
wooden
plug
for
It
a measure
whIch
IS sometImes
wItnessed the COndItIOn mSlde of the tank becomes the
same
as though
It were sealed up
Always
use
only
the standard cap
Operation
and
Repairs
of
Fuel
Gauge
As shown
In
FIg
3 the fuel gauge
consIsts
of the dash
UnIt
and tank
unIt
The dash
UnIt
wmch
IS
Installed
on
the
Instrument panel
has
two
cOIls that
cross
each other
at
nght angles
whose
magnetIc
forces control the
movement
of
a
keeper
Iron
pIece
WIth
a
hand IndIcator
On the tank
UnIt
a
contact
arm
slIdes
over a
resIstance
In
response
to
the
float level
As shown
In
FIg
3 If the
IgnItIOn
SWItch
IS
turned
on
when the
tank
IS
empty
electnc
current
wIll flow from the
battery through
the
ammeter Into
coIl
A and
then
through
the
contact arm
to the
ground
CoIl A
IS
then
magnetIzed attracts
the
Iron
pIece
and the IndIcator pOInts
to
E
As the float
IS
raIsed and the
contact arm moves
tank
UnIt Increases reSIS
tance
In
the
CIrCUIt
and thus the
current
wmch traveled
through
COIl A then flows
tms
tIme
both
contact arm
and coIl B and
fInally
to
the
ground
As both A
and
B cIls
are so
wound
as to
have theIr
magnetIc
poles
In
the
same
dIrectIOn
the
Iron
pIece wIll
rotate to
the
dIrectIon where the
magnetIc
power of
the
two
COIls
can be balanced
wIth
the IndIcator
deflectIng
In
the dIrectIOn of
F
That
IS thIS
IS a
gauge of electnc
resIstance
control
type
E
SIgnIfIes
Empty
level and
F Full level
Troubles
with Fuel
Gauge
and their
Remedies
When
somethIng
IS
wrong
WIth
the
readIngs
of he fuel gauge
fIrst dIS
connect
the wlnng
at
the
UnIt
and
turnIng on
the
IgnItIOn
SWItch
ground
and
un
ground
the termInal end
of
the saId wlnng
to
the
body
of the
car
If the IndIcator
of the
dash
UnIt
SWIngs
actIvely
between E and F the wlrmg
between the dash
UnIt
and the saId termInal end
IS In
good
condItIon WIth the de
fect
eXIstIng
either
In
tank
unIt
Itself
or In
poor
ground
of thIS
UnIt
In the
test
mentIOned
In
the
preceedIng sectIon
If
the
IndIcator does
not
SWIng
but
It moves
moves to
E
when
the dash
UnIt
end
of the wlnng from the
tank
UnIt
IS grounded
the wlnng between the dash
UnIt
and tank
UnIt IS defectIve
Therefore reWIrIng
or
repalnng
IS
requIred
If when IndIcator flals
to
swmg but
sparkIng
IS
observed when the WIrIng
connectIng
the
battery
wIth the termInal
on
the dash
UnIt
IS
dIsconnected
at
the
dash
UnIt end and
grounded
It
proves the wirIng
IS
satIsfactory
and the trouble
IS In
the dash
UnIt
Itself
If
sparkIng
does
not
occur
the WIrIng wmch
IS
thus
IndIcated
to
be
out
of
order should be
repaIred
or
replaced
Incorrect
readIngs
of the IndIcator
probably
means
that the
heIght
of the float
of the tank
UnIt
IS m error
In thIS
case
adjust
the
heIght
of the float
by bendIng
the rod
Troubles
with
the
UnIt are
dIffIcult
to
repaIr
so It
should be
replaced by a new
unIt
S8