Starter Solenoid - MCi MC8 Crusader Maintenance Manual

MAINTENANCE
Crusader
MC-8
[,.u_7_-1_6 _ _ _
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_19_73 _ _ ]
MANUAL
Pinion clearance is adjusted to these limits by tur-
ning the solenoid shaft nut after removing access plug
in shift housing. See Fi1a?ure 7-14.
STARTER SOLENOID
DESCRIPTION
The starting motor solenoid shifts the starting
motor pinion into mesh with the flywheel ring gear
and also closes the electr+cal circuit to energize the
starting motor.
There are two windings in the solenoid: a pull-
in winding and a hold-in winding. Both windings are
energized when the external control switch is closed.
They produce a magnetic field which pulls the plun-
ger in so that the drive pinion is shifted into mesh,
and the main contacts in the solenoid switch are
closed to connect the battery directly to the starting
motor. Closing of the main switch contacts shorts
out the pull-in winding since this winding is con-
nected across the main contacts. The magnetism
produced by the hold-in winding is sufficient
!O
hold the plunger in, and shorting out the pull-m
winding reduces drain on the battery. When the
control switch is opened, it disconnects the hold-in-
winding from the battery. When the hold-in winding
is disconnected from the battery the shift lever
spring withdraws the plunger from the solenoid,
opening the solenoid switch contacts and at the
same time withdrawing the drive pinion from mesh.
Proper operation of the switch depends on maii:i-
taining a definite balance between the magnetic
strength of the pull-in and hold-in windings.
l.
Starter Solenoid Installed
This balance is established in the design by the size
of wire and the number of turns specified. An open
circuit in the hold-in winding or attempts
t?
start
with a discharged battery may cause the switch to
chatter.
DISASSEMBLY
To disassemble the solenoid, remove nuts, washers,
and insulators from the switch terminal and battery
terminal. Unscrew cover screws and remove cover.
Take out the contact disk assembly.
SOLENOID TESTS
Two tests must be made to determine the current
draw of
(I)
both windings in pa_rallc:l a_nd (2) the
hold-in winding alone. The solenoid wmdmgs can_ be
tested with the solenoid either off or on the startmg
motor. However, when the solenoid is checked on the
starting motor, it is ne1::essary
!o
disconnect b<?th
leads at the main solenoid termmals to prevent m-
terference. The main solenoid terminal which is nor-
mally connected to the starting motor must t?en be
grounded to the solenoid base by means of a JUI_Tlper
lead. For the first test, connect a source of _vana~le
voltage (battery and a variable resis~ance) m senes
with an ammeter between the solenoid base and the
solenoid small switch terminal. Connect a voltmeter
between the same two points. Slowly increase voltage
and note the current draw. This should be 55-63
amps at 24 volts. Disc<:>nnect t~e jumper lea~ groun-
ding the main solenoid t~rmmal a~d. read3ust the
variable resistance to obtam the spec1f1ed voltage of
24 volts. This should not exceed 6.8 amps.
When the solenoid has been removed from the star-
ting motor for repair or replacement, the li~k~ge
must be adjusted to provide the correct pm10n
clearance when the solenoid is remounted on the
starting motor. See "Starting Motor" e3:rlier in this
section for correct pinion clearance ad3ustment.
BATTERIES
DESCRIPTION
Two
J
2-Volt batteries are connected in series,
mounted in a compartment behind the fut:l tank com-
partment door on the right hand front_ side._ Battery
cells may be checked and filled at this pomt.
IMPORT ANT: Observe decal on inside of battery
compartment for proper connections.
The battery has three major functions to perform
on the vehicle.
(I)
It provides a source of current for starting the
engine.
(2) It acts as a stabilizer to the voltage in the elec-
trical system.
(3) It can for a limited time, furnish current when
electri'cal demands of the electrical equipment
exceed the output of the generator.
In replacing batteries, only batteries of the same