MG MGB - Page 319

MGB. Issue
1. 85699
Na.ll
Test
Procedure
Using
test
lamp
to
bridge
plug pins
Using cable only
to
bridge
plug pins
Circuit
Requirements Remarks
Supply from battery
2and5
Positive
battery feed
to
earth
Test
lamp
ON
If the
test
lamp
does
not
operate,
the circuit is faulty.
Driver’s
seat
belt
switch
2andll
Positive
battery feed
via
belt switch
to
earth
(a)
Test
lamp
ON—
seat
belt
unfastened
(b)
Test
lamp
OFF——
seat
belt fastened
If
the
test
lamp does
not
operate
in
(a)
or
lights in (b)
either
the
seat
belt switch
or
the
circuit
wiring is
faulty.
Driver’s
seat
switch
5
and
10
Positive
battery
feed
via
driver’s
seat
switch
to
earth
(c)
Test
lamp
ON—
driver
seated
(d)
Test
lamp
OFF——
driver
unseated
If
the
test
lamp
does
not
operate
in (c)
or
lights
in (d),
either
the
seat
switch
or
the
circuit
wiring is faulty.
Passenger’s
seat
belt
switch
2and9
Positive
battery feed via
belt
switch
to
earth
(e)
Test
lamp
ON—
seat
belt unfastened
(f)
Test
lamp
OFF—
seat
belt fastened
If
the
test
lamp
does
not
operate
in
(e)
or
lights
in (f),
either
the
seat
belt switch
or
the
circuit
wiring is faulty.
Passenger’s
seat
switch
5
and
12
Positive
battery feed via
passenger’s
seat
switch
to
earth
(g)
Test lamp ON—
passenger
seated
(/1)
Test
lamp
OFF——
passenger
unseated
If
the
test
lamp
does
not
operate
in (g)
or
lights in
(h),
either the
seat
switch
or
the
circuit wiring is faulty.
Gearbox
switch
4
and
5
(ignition
on)
Positive
battery feed
via
ignition and
gearbox
switches
to
earth
Test lamp
ON—
gear
engaged
If the
test
lamp
does
not
operate
when
a gear
is
engaged,
either
the ignition
or
the
gearbox switch,
or
the circuit wiring
is faulty.
If the
test
lamp lights
when
the
gear
lever
is in
neutral,
the gearbox
switch
is
faulty.
THE
ELECTRICAL
SYSTEM
Na