1935 Cadillac - GM Heritage Center

Cadillac Preliminary Service Information 25
Rela
Solenoid Windings
Ammeter
flLlenl
Plunge,
engine starts running, the solenoid circuit is automatically
opened which allows the starting gear to
disengage from the flywheel. The relay circuit is
controlled by the ignition switch in such a manner
that the solenoid is inoperative unless the ignition
switch is in the "on" position.
I
\—'
Starter Button \ Storage ^ r
(Generator Ignition'Switch
I. Battery
' Starting Motor
Fig. 32. Diagram of the starting motor
circuit
the "C" series cars. The control for the starting
motor, however, is entirely new and cor/sists of a
solenoid mounted on top of the starting' motor, a
relay and a starter button on the instrument panel.
To start the engine in the new cars, it is only
necessary for the driver to turn on the ignition
switch and then press in on the hand starter button.
The solenoid operates the starter engaging
mechanism and is controlled by a relay'both of
which are shown in Fig. 30. The relay in turn is
controlled by the starter push button on the instrument
panel and serves the same purpose in the
solenoid and starter button circuit as docs the horn
relay in tb.6 horn circuit; that is, instead of a heavy
wire being used between the starter button and the
solenoid, heavy wires are used only between the
relay and the solenoid. A smaller wire is used between
the relay and the starter button. This will
eliminate the passing of a heavy current through
the starter button and making a voltage drop in
the wiring.
The solenoid serves two purposes. It operates
the starter switch and the gear shifting mechanism
in the starting motor. When sufficient current is
passed through the solenoid winding, the plunger
is moved frontward engaging the starter pinion
with the flywheel ring gear and also closing the
starting motor circuit through the contacts shown
in Fig. 33-
There is one adjustment on the starting motor
assembly and that is on the solenoid plunger to
secure the proper mesh of the starting pinion with
the flywheel ring gear. To make this adjustment,
the starter should be removed from the engine.
. Then remove the pin in the upper end of the shifting
yoke and push the solenoid plunger all the way in
the solenoid after which move the pinion all the
way back to what would be the engaged or cranking
position if the starter were mounted in the
engine, taking out all backlash in the shifter
mechanism. Next move the pinion }/% in. frontwards
away from the end of the housing and adjust
the stud in the solenoid plunger by turning it to the
right or left as required until the pin may just be
inserted at the forward end of the slot.
All other service on the solenoid unit can be obtained
from United Motors Service. Distributors
The relay is essentially an electromagnet, consisting
of a winding and core, a base and an armature.
The winding is connected in series with
the starter button, the ignition switch and the
generator as shown in Figs. 31, 32 and 34. When
the core is sufficiently energized, the armature is
pulled down closing the solenoid circuit, thus
operating the solenoid plunger. The smaller solenoid
winding is the holding coil to keep the plunger
in the engaged position.
The starter relay is connected in the electrical
system in such a way that when the generator is
charging, the relay is inoperative. This means
that when the engine is running, the starter gear
cannot accidentally be engaged. Also when the
Fig. 33. The starting motor switch forms a part of
the solenoid unit