Starting System-General Information And Precautions; Starter Motor-Testing In Vehicle; Starter Motor-Removal And Installation - Jeep cherokee 1989 Owner's Manual

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18.10 To hold the brushes in place during reassembly, insert
a paper clip through the hole in the end frame nearest to the
rotor shaft
10 When installing the brushes in the brush holder, install the brush
closest to the end frame first. Slip the paper clip through the rear of
the end frame to hold the brush, then insert the second brush and
push the paper clip in to hold both brushes while reassembly is com-
pleted (see illustration). The paper clip should not be removed until
the front and rear end frames have been bolted together.
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general information and precautions
The sole function of the starting system is to turn over the engine
quickly enough to allow it to start.
The starting system consists of the battery, the starter motor, the
starter solenoid, a remote starter relay (on some models) and the wires
connecting them. A number of different starter motors
Bosch, Delco, Mitsubishi and Motorcraft
covered by this manual. If you replace the starter motor, be sure to
take the old starter with you to the parts department to make sure you
get the right replacement. The solenoid is mounted directly on the
starter motor or, on Motorcraft units, is a separate component located
in the engine compartment.
The solenoid/starter motor assembly is installed on the lower part
of the engine, next to the transmission bellhousing.
When the ignition key is turned to the Start position, the starter
solenoid is actuated through the starter control circuit. The starter
solenoid then connects the battery to the starter. The battery supplies
the electrical energy to the starter motor, which does the actual work
of cranking the engine.
The starter on a vehicle equipped with an automatic transmission
can only be operated when the transmission selector lever is in Park or
Neutral.
Always observe the following precautions when working on the
startina svstem:
serious damage. Never operate the starter motor for more than
15 seconds at a time without pausing to allow it to cool for at
least two minutes.
The starter is connected directly to the battery and could arc or
cause a fire if mishandled, overloaded or shorted out.
Always detach the cable from the negative terminal of the battery
before working on the starting system.
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Starter motor testing in vehicle
Note: Before diagnosing starter problems, make sure the battery is
fully charged.
1 If the starter motor does not operate at all when the switch is
The Motor Manual Guy
Chapter 5 Engine electrical systems
turned to Start, make sure the shift lever is in Neutral or Park (auto-
matic transmission).
2
the battery and starter solenoid terminals, are clean and secure.
3
running clutch in the starter motor is slipping and the starter motor
must be replaced.
4
at all but the solenoid clicks, then the problem lies with either the bat-
tery, the starter relay (if equipped), the main solenoid contacts or the
starter motor itself (or the engine is seized).
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ated, the battery is bad, the fusible link is burned (the circuit is open) or
the solenoid itself is defective.
6
- including
(+) and the ignition switch wire terminal (the small terminal) on the
- are used on the vehicles
solenoid. If the starter motor now operates, the solenoid is OK and the
problem is in the ignition switch, neutral start switch or the wiring.
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first make sure that the battery is charged and that all terminal connec-
tions are tight. If the engine is partially seized, or has the wrong viscos-
ity oil in it, it will crank slowly.
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then disconnect the coil wire from the distributor cap and ground it on
the engine.
10 Connect a voltmeter positive lead to the positive battery post and
connect the negative lead to the negative post.
steady figure is indicated. Do not allow the starter motor to turn for
more than 15 seconds at a time. A reading of 9 volts or more, with the
starter motor turning at normal cranking speed, is normal. If the read-
ing is 9 volts or more but the cranking speed is slow, the motor is
faulty. If the reading is less than 9 volts and the cranking speed is
slow, the solenoid contacts are probably burned, the starter motor is
bad, the battery is discharged or there is a bad connection.
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Refer to illustrations 21.3, 21.4a and 21.4b
Note: On some vehicles, i t may be necessary to remove the exhaust
extreme cases it may even be necessary to unbolt the mounts and
raise the engine slightly to get the starter out.
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21.3 Before unbolting the starter motor assembly, detach the
wires (arrows) from the solenoid (or from the starter motor itself
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on some models) be sure the battery is disconnected!
Make sure that the battery is charged and that all cables, both at
If the starter motor spins but the engine is not cranking, the over-
If, when the switch is actuated, the starter motor does not operate
If the solenoid plunger cannot be heard when the switch is actu-
To check the solenoid, connect a jumper lead between the battery
If the starter motor still does not operate, remove the
If the starter motor cranks the engine at an abnormally slow speed,
Run the engine until normal operating temperature is reached,
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Starter motor removal and installation
Detach the cable from the negative terminal of the battery.
Raise the vehicle and support it securely on jackstands.