MG MGB User Manual

THE
ELECTRICAL
SYSTEM
_
N
WIPER
TAKES
ABNORMALLY LOW
CURRENT
Check
that the battery
is
fully charged.
The performance
of
the
motor
is
dependent
on
the condition
of the battery.
Remove the
commutator
end bracket
and
examine
the
brush
gear,
ensuring
that
it
bears
■rmly
on
the
commutator.
The
tension spring
must
be
renewed if the
brushes do
not
bear
firmly
on
the
commutator.
Brush levers
must
move
freely
on
the
pivots.
If these levers
are
stiff they
should be
freed by
working
them
backwards and
forwards
by
hand.
Examine
the
commutator
and,
if
necessary,
clean with
a
fuel-moistened
cloth.
A
suspected
armature
should be
checked
by substitution.
WIPER TAKES
ABNORMALLY HIGH
CURRENT
If
an
abnormally
high
current
is
shown
on
the
ammeter,
this
may
be
due
to
excessive
load
on
the driving
shaft. The
stall
current
of the
motor
when cold
is
14
amps.
and
when
hot
is
.8
amps.
If there
is
no
obvious
reason
for this,
such
as a
sticking
wiper
blade,
a
check
should be
made
at
the
gearbox.
Remove
the gearbox
cover
and
examine
the
gear
assembly,
checking
that
a
blow
on
the
gearbox end
bracket has
not
reduced the
armature
end-■oat. The
armature
end-■oat
adjusting
screw
must
be
set
to
give
an
armature
end-play
of
.008
to
.012
(.20
to
.30
mm.).
Sluggish
operation
with excessive
current
consumption
may
be
caused
through frictional losses
in
badly
positioned
or
defective connecting
tubes.
The
connecting
tubes
can
be
checked,
using
a
cable
gauge.
(Details of
this
gauge can
be
obtained from
any
Lucas
Agent.)
The
gauge
cable
is
similar
in
appearance
to
the
driving rack
but
is
.010
in.
(.25 mm.)
larger
in
diameter
and
is
less
■exible. The
gauge
will
not
easily
pass
through
connecting
tubes
having less
than the
minimum
permissible
curvature.
SOGZBW
Fig.
N.12
Wiper
arm
■xing
details
1.
Retaining clip.
2.
Splined drive.
MGB.
Issue
5.
25729
3.
Locking
screw.
4. Locking
wedge.
A1277AW
Fig.
N. 1
3
Windshield wiper
drive
components
1.
Cross-head
5.
Final
gear.
2.
Cable
rack.
6.
Park switch.
3. Outer
casing.
7.
Connecting
rod.
4. Armature.
To
check the tubing
remove
the
motor
and
inner
rack.
Insert
the
gauge
into
the
connecting
tube
as
far
as
the
first
wheelbox and
then withdraw
it.
Remove
the tubing
connecting
the
wheelboxes.
Insert
and
withdraw the
gauge.
If
the
gauge
moves
freely the tubing
is
correctly
installed. If
the
gauge
does
not
move
freely the tubing
must
be
checked
for sharp bends
and obstructions. Check
the wheelboxes
for
alignment
and then reassemble.
Removing
the
motor,
gearbox,
and wheelboxes
The
motor
and gearbox
is
located beneath the
passenger’s
side of the fascia
panel
and
is
mounted
on
a
bracket
secured
to
the
bulkhead
panel by
three
screws.
The
cable rack
connected
to
the
cross-head
in
the gearbox
passes
through
outer
casings
which
connect
the gearbox
to
the ■rst wheelbox
and
the ■rst wheelbox
to
the
second
wheelbox.
Disconnect
the
wiper
arms,
the electrical
connections
from
the
motor,
and the
outer
cable
from the gearbox housing.
Remove
the three
screws
securing
the bracket
to
the
bulkhead panel
and
withdraw the
motor,
bracket, and
cable
rack
from beneath the fascia panel.
Slacken
the
cover screws
in
each wheelbox and
remove
the
cable rack
outer
casings.
Remove the
nut,
front bush, and
washer
from the front
of
each wheelbox
and
remove
the
wheelbox together with the
rear
bush and
spindle tube
from beneath the fascia panel.
Replacement
is
a
reversal
of the
removal
sequence,
but
care
must
be
taken
to
ensure
that
the wheelboxes
are
correctly
lined
up
and that the
cable rack
engages
the
gear
and
spindle
assemblies.
N.15

MG MGB Specifications

General

Brand	MG
Model	MGB
Category	Automobile
Language	English