GMC 4000 Series Service Manual page 408

CONTACT
FINGER
CONNECTORS
B U S H IN G
When engine control switch is placed in "START
position, current from the battery is supplied
through engine control switch and closed contact
points of starter interlock relay to energize starter
solenoid. When engine is started and reaches ap­
proximately 400-600 rpm, current from generator
"R" terminal is supplied through starter interlock
relay operating coil to break circuit to starter
solenoid, thus disengaging the starter ii engine
control switch is not released after engine is
started. This also prevents starter from being
accidentally engaged by turning engine control
switch to "START" position while engine is running.
SERIES DLA/DLV-4000
A starter control relay is used on these ve­
hicles to prevent starter over-speeding by break­
ing starter solenoid-to-engine control switch cir­
cuit when engine reaches approximately 400-600
rpm. This system also prevents starter pinion from
engaging a running flywheel by breaking circuit
between engine control switch and starter solenoid
while engine is running. This system is controlled
by output at "R" terminal of generator as shown in
figure 4.
G M C S E R V I C E M A N U A L
GROMMET PLUNGER
ARMATURE
FIELD CO IL__
INSULATED BRUSH HOLDER
BRUSH SPRING
GROUNDED BRUSH HOLDER
Figure 1 — O verrunning Clutch Type Starting Motor (Typical)
SOLENOID RETURN SPRING
OVERRUNNING
CLUTCH
SPIRAL SPLINES
When engine control switch is placed in "START"
position, current from the battery is supplied
through engine control switch and closed contact
points of starter control relay to energize starter
solenoid. When engine is started and reaches ap­
proximately 400-600 rpm, current from generator
"R" terminal is supplied through starter control
Figure 2 — Starter D ise n ga ge m e n t a n d
Lock-Out (S C 5 5 0 0 ) (Typical)
Sec. 6Y
Page 397
STARTING SYSTEM
SHIFT LEVER
BUSHING
PINION STOP
TPM -6606-2