Starter Control Circuit Tests; Starter Solenoid Test; Starter Relay Test; Test Starter Motor Ground - Dodge D150 1990 Service Manual

8A - 12 BATTERY/STARTING/CHARGING SYSTEMS DIAGNOSTICS
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(3) Rotate and hold t h e i g n i t i o n switch (key) i n t h e
START position. I f voltage reads above 0.2 volt, cor-
rect poor contact a t g r o u n d cable a t t a c h i n g p o i n t .
Voltage r e a d i n g s t i l l above 0.2 v o l t , replace g r o u n d
cable.
(4) Remove starter h e a t shield ( i f equipped) t o g a i n
access t o t h e starter motor and solenoid connections,
perform t h e following:
(a) Connect positive voltmeter lead t o t h e
starter motor housing and the negative lead t o t h e
b a t t e r y negative t e r m i n a l (Fig. 7). Rotate and h o l d
t h e i g n i t i o n switch (key) i n t h e S T A R T position. I f
voltage reads above 0.2 volt, correct poor starter t o
engine ground.
STARTER
MOTOR
BATTERY
VOLTMETER
898A-26
Fig. 7 Test Starter Motor Ground (Typical)
(b) Connect positive voltmeter lead t o positive
b a t t e r y t e r m i n a l a n d negative lead to battery cable
t e r m i n a l o n starter solenoid ( F i g . 8). Rotate a n d
h o l d t h e i g n i t i o n s w i t c h (key) i n t h e S T A R T posi-
t i o n . I f voltage reads above 0.2 volt, correct poor
contact a t battery cable to solenoid connection. I f
reading i s s t i l l above 0.2 volt, replace positive bat-
t e r y cable.
BATTERY
STARTER
MOTOR
VOLTMETER
898A-20
Fig. 8 Test Positive Battery Cable Resistance
(Typical)
I f resistance tests detect no feed circuit failures, r e -
move the starter motor and proceed to Bench T e s t i n g
S t a r t e r Solenoid.
STARTER CONTROL CIRCUIT TESTS
The starter control circuit consists o f a starter so-
lenoid, starter relay, i g n i t i o n switch, safety n e u t r a l
s w i t c h (automatic transmission), and a l l t h e i r w i r i n g
a n d connections.
Testing procedures for these components are as fol-
lows and should be followed i n order as described.
CAUTION: Before performing any test disconnect
distributor connector to prevent engine from start-
ing.
STARTER SOLENOID TEST
Connect a heavy j u m p e r w i r e on starter relay be-
tween battery (1) and solenoid (3) t e r m i n a l s (Fig. 9).
I f engine cranks starter solenoid is good. Proceed t o
starter relay test.
SOLENOID TERMINAL
NEGATIVE
BATTERY
CABLE
— \ —
BATTERY
CABLE
TO STARTER
FIELD TERMINAL
STARTER
MOTOR
BATTERY
RELAY FEED
Z
HEAVY
JUMPER
WIRE
®
BATT.
(f)SOL.
0 I G .
SW.
BATTERY
STARTER
RELAY
RH477A
Fig. 9 Starter Solenoid Test
I f the engine does not crank or the solenoid chat-
ters, check w i r i n g a n d connectors from relay t o
starter for loose or corroded connections, p a r t i c u l a r l y
at starter t e r m i n a l s . Repeat test and i f engine s t i l l
fails to crank properly trouble is w i t h i n starter a n d
i t m u s t be removed for repairs.
STARTER RELA Y TEST
(1) Position gear selector i n n e u t r a l (manual) o r
p a r k (automatic) position.
(2) Set p a r k brake.
(3) Do not remove relay connector.
(4) Check for battery voltage between starter relay
b a t t e r y (1) t e r m i n a l and ground w i t h a test l a m p .
(5) Connect a j u m p e r w i r e on the starter relay be-
tween battery and (1) i g n i t i o n (4) terminals (Fig. 10).
I f engine cranks starter relay is good.
(6) I f engine does n o t crank connect a second
j u m p e r w i r e t o starter relay between ground t e r m i -
n a l a n d to a good ground (5) (Fig. 11). Repeat test