START I N G SY ST EM
TABLE OF CONTENTS
page page
STARTING SYSTEM
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 28
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
DIAGNOSIS AND TESTING - STARTING
SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
SPECIFICATIONS
TORQUE - STARTER - DIESEL . . . . . . . . . . . 33
SPECIFICATIONS - STARTER MOTOR -
DIESEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
STARTER MOTOR
DIAGNOSIS AND TESTING - STARTER
MOTOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 35
STARTER MOTOR RELAY
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 35
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 36
START I N G SY ST EM
DESCRIPTION
The starting system consist s of:
• Star ter relay
• Starter motor (includin g an integra l star ter sole-
noid)
Other compon ents to be considered as part of start-
ing s ys te m are :
• Ba t t er y
• Ba tter y cables
• Ignit ion switch and key lock cylinder
• Park/neutral position switch (au tomatic tr ans-
mission )
• Wire h arnesses a nd connection s.
The Battery, St arting, a nd Char ging system s oper-
ate in conjun ction with one another, and mu st be
tested as a complet e system . For correct oper ation of
st arting/ch arging system s, a ll com pon ents used in
these 3 syst ems mu st perform within specifications.
When attempting to dia gnose any of these system s, it
is important t hat you keep th eir in terdepen dency in
mind.
The dia gnostic procedu res used in each of these
groups include th e most basic conven tiona l dia gnostic
meth ods, to th e m ore sophistica ted On -Board Dia g-
nostics (OBD) bu ilt into the Engine Control Modu le
(ECM). Use of an induct ion-type milliamper e a mme-
ter, volt/ohmmeter, battery cha rger, carbon pile rh eo-
st at (load tester), an d 12-volt test lamp ma y be
required.
Certain st arting system componen ts a re monitored
by the E CM and m ay pr odu ce a Dia gnostic Trou ble
Code (DTC).
OPERATION
The st arting system componen ts form t wo separa te
circuits. A high-a mperage feed cir cuit that feeds t he
st arter motor high -amperage, a nd a low-amper age
control circuit tha t operat es on less t han 20 a mperes.
The high-am perage feed circuit componen ts in clude
the bat tery, the ba tter y cables, th e cont act disc por-
tion of t he sta rter solenoid, a nd th e sta rter motor
itself. The low-amperage cont rol circuit components
include the ignition switch , the pa rk/n eutr al position
switch (automa tic transmission), th e sta rter r elay,
the electromagn etic windin gs of th e starter solenoid,
and the connect ing wir e har ness components.
If the veh icle is equipped with an a utomatic tran s-
mission , batt ery voltage is su pplied thr ough the low-
amper age cont rol circu it to t he coil batt ery termina l
of the star ter rela y wh en t he ignition switch is
turned to the m oment ary Star t posit ion. The park/
neut ral position swit ch is insta lled in series between
the sta rter r elay coil gr ound ter minal a nd grou nd.
This n ormally open switch prevent s t he sta rter rela y
from being energized and the star ter motor fr om
operat ing unless the automat ic transmission gea r
selector is in th e Neutr al or Park posit ions.
When the st arter relay coil is ener gized, the n or-
mally open relay contacts close. Th e relay cont acts
connect t he relay common feed ter mina l to the relay
normally open termina l. The closed relay contacts
energize the star ter solen oid coil windings.
The energized solenoid pu ll-in coil pulls in the sole-
noid plun ger. Th e solenoid plunger pu lls the sh ift
lever in th e sta rter motor. This enga ges the starter
overr unning clu tch and pinion gea r wit h the star ter
ring gear on the man ual transmission flywh eel or on
the a utomatic transmission tor que con vert er or
torqu e converter dr ive plate.
As the solenoid plun ger reaches the end of its
travel, th e solenoid con tact disc completes the h igh-
amper age starter feed circuit and en ergizes th e sole-
noid plun ger hold-in coil. Current now flows between
the solenoid bat tery terminal a nd the sta rter motor,
en er gizin g t h e st a r t er.
Once the en gine starts, t he overr unning clutch pro-
tects the star ter motor from da mage by a llowing the
8F - 28 STARTING SYSTEM VA
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