MASSEY FERGUSON MF 14 - Page 55

MASSEY.FERGUSON
GROUP
O-SECTION V-PART 4
TECUMSEH
HH1OO
& HH|2O ENG'AIES
ELECTRICAL
SYSTEM
The electrical
system in the
MF 12
Tractor Engine
is
a
"Solid
State" system in which the
conventional
generator,
regulator,
coil,
points
and
breaker
cams
have
been
eliminated.
In
their
place
there
has
been
installed
a
regulator-rectifier;
ignition
unit with
built-
in
coil; and
flywheel alternator to
provide
electrical
current.
This is a
proven
system and is less troublesome
than
the
previously
used
electrical
system.
As an
example,
spark advance
due to
point
gap
changes
does not
occur in the
solid state system.
Do not
confuse this
"Solid
State" system with the
transistor
system
used
in
some modern automobiles.
A
mechanic,
using specified test
equipment will
have
no
difEculty in diagnosing
and correcting
prob-
lems
which
may
occur.
SERVICING
ALTERNATOR
CHARGING
SYSTEM
A. Precautions
1.
Do not
connect
battery to cables in tvrong polar-
ity.
This
will
cause regulator-rectifier
damage.
2.
Break
continuity
betrveen the regulator-rectifier
unit
and battery when
using a remote
charger
on the
battery,
or
when
]umping"
from
another
battery.
This
will
eliminate
damage to the regu-
lator-rectifier
if
polarity
is reversed.
3.
Disconnect
wiring harness
at
regulator-rectifier
before
using trrc welder
on equipment.
B.
Pre-Seroice
Checks
I.
Check
for
good ground
betrveen regulator-recti-
fier
and
mounting.
2.
Check for poor
connections
or broken rvires.
C. Trouble-Shooting
l.
Battery not
fully charged.
2.
Disconnect
B*
at fuse coupling
and check
D.C.
voltage
between
coupling
and
ground
with
en-
gine
mnning at
full throttle.
Fig. l.
a. If voltage
reading
is
above
"14"
volts,
D.C.
system is
O.K.
b. If ammeter
does not
show
charge,
or with
lights
on ammeter
does not
show discharge,
check
wiring.
If wiring
is
O.K.,
replace
ammeter.
Revised
4/7O
Fig. 1
Fig.
VOLTMETER
LEAM
Fis.
3
B+
TERMINAL WIRE
D.
C.
VOLTMETER
LEADS
REGULATOR-
RECTIFIER