Download Starter System Service

Starter System Service
Chapter 33
Page 439
Service Begins with Checking System
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Check the battery first –Voltage should be 12.6
and while the starter is trying to work, the
voltage can’t drop below 9.6 volts
Turn the headlights on—
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If they don’t work, the battery is dead
If they dim tremendously, the battery is near dead
If they stay on bright, then there may be a bad component
(solenoid, switch, wiring problem, terminal loose)
Testing System
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Disable the ignition
Remove center ignition wire and ground it to metal
 Disconnect the wiring harness from distributor
 Remove ignition fuse
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Cranking rpm should be 250 or more
*Starters are designed for short running times,
Don’t run it long!
Testing System
Voltage Drop Test
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This test checks the individual components to
make sure each is operating properly.
Loss of voltage = High resistance = High heat
A drop of . 1 volts or more in connections and
.4 volts between starter and engine needs to be
cleaned and checked.
A dirty and corroded terminal to clamp
connection can rob up to 12 volts from the
starting circuit voltage.
Check Terminal to Clamp
Connection
Pos
No more than .1 volts
Neg
Check Clamp to Cable Connection
Pos
Neg
No more than .1 volts
Check the Battery Cable
No more than .1 volts
Check the Ground
Should be 0 volts
Problems
Cable frays are going to
cause high resistance
Heat damage from high resistance
Follow a Step by Step Process
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Problem: Cranks slow. Test #1 - Make the following checks first:
Fully charged battery
Clean battery terminals
Inspect Pos. and Neg. cables for proper routing and clean tight connections.
Test #2 - Measure the battery voltage before you start. Pos. lead of Voltmeter to Pos. terminal of battery and
the Neg. lead of Voltmeter to Neg. terminal of battery. 12.5 volts or better is good, if less then charge the
battery first. Attempt to crank the engine and note battery voltage, 9 volts is minimum. Anything less indicates
a poorly charged or bad battery.
Test #3 - Check the ground system. This test checks the integrity of the entire ground system from the
battery to the engine block. Leave your Neg. Voltmeter lead hooded to the Neg. battery terminal and move
the Pos. lead of Voltmeter to a clean ground on the engine. Attempt to crank the engine and note the battery
voltage. Any reading above 0.2 volts while cranking is bad. My reading was 1.09 volts.
Test #4 - Check the Pos. side. This test checks the integrity of the entire Pos. side of the starting system
between the battery and the starter. Remove your test leads and hook the Pos. Voltmeter lead to the Pos.
battery terminal and hook the Neg. Voltmeter lead to the starter motor terminal. (Cable from solenoid to
starter.) Attempt to crank the engine and note the Voltmeter readings (ignore Voltmeter reading before
cranking). Any reading above 0.3 volts is bad. My reading was 3.48 volts.
Test #5 - Check the starter cable. Remove Pos. Voltmeter lead from battery and hook it to the starter side of
the solenoid and note Voltmeter reading while attempting to crank the engine. Any reading above 0.2 volts is
bad. My reading was 2.43 volts.
Test #6 - Check the solenoid contacts. Hook your Voltmeter Pos. lead to the battery terminal side of the
solenoid and the Voltmeter Neg. lead to the starter terminal of the solenoid (ignore Voltmeter reading before
cranking) and note Voltmeter reading while attempting to crank the engine. Any reading above 0.1 volt is bad.
My reading was 0.07 volts.
Test #7 - Check the battery cable to starter solenoid. Hook Voltmeter Pos. lead to Pos. battery terminal and
voltmeter Neg. lead to battery side of solenoid. Attempt to crank the engine and note Voltmeter readings. Any
reading above 0.2 volts is bad. My reading was 1.01 volts.
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Interpreting the test results:
Test #1 will solve many starting problems.
Test #2 will test the basic integrity of your battery.
Test #3 Ground system. Result of test indicates a poor ground condition. Visual inspection revealed
loose and corroded battery cable to terminal connections. Block connection was good. The proper
repair will be a new Negative battery cable.
Test #4 Positive side. Result of test indicates poor connections (too much resistance).
Test #5 Starter cable. Result of this test indicates a poor connection or cable. Visual inspection
confirmed a bad cable, melted insulation at terminal connector for solenoid. This cable needs replacing.
Test #6 Solenoid contacts. This test indicated good solenoid contacts. No problem here.
Test #7 Battery cable. This test indicated poor connections. Visual inspection confirmed dirty
connection between battery terminal and cable.
Make the needed corrections indicated by the tests above and retest the system to confirm the repairs
you made were effective. If it still cranks slowly, the starter motor is bad. Problem: Engine does not
crank, solenoid chatters or doesn't click
1. Complete test #1 and #2 above.
2. Check ignition switch. This is a quick test of the circuit between the battery and the solenoid. Remove
the wire going to the solenoid "S" terminal and hook up your Should be 12 volts or more.
3. Check the solenoid ground. This test assumes your ignition switch circuit is good. Use your Voltmeter
to perform a voltage drop test to confirm the ground. Hook the Neg. lead of Voltmeter to Neg.
terminal of the battery and the Pos. lead of Voltmeter to the ground lug or bolt of the solenoid. Attempt
to crank engine and note the volt reading on your Voltmeter. Less than 0.2 volts, good reading, no
problem with ground. More than 0.2 volts indicates a poor ground to the solenoid. No reading would
indicate a possible open circuit in the solenoid itself. Substitute a known good solenoid or remove the
solenoid and test as per your Repair guide. There should be a resistance value in your Repair guide for
the "S" terminal to ground. A 0 (zero) ohms reading would indicate a shorted winding and an (infinity
reading) would indicate an open winding. Any other reading should be compared against the specs in
your Repair guide. If the results of your tests confirm the solenoid is good, verify the ground cable
between the battery and engine block to make sure it is good. If the solenoid tests good and the ground
cable is good, then the starter motor is bad.
Neutral Safety Switch
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This needs to be checked if you don’t get 12
volts at the “S” terminal on the solenoid.
Both auto and manual transmissions have this
safety device.
Check the Shop manual for location and repair
of the neutral safety switch.
Starter Repair
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Starter repair is almost down to just replacement!
The cost is to high to try to repair or rebuild the starter
Most repairs are cleaning the terminals, replacing the
solenoid, replacing the drive gear, and cleaning
corrosion off the armature---the gear and armature
repairs require breaking the starter down--- probably
won’t do this anymore.
Adjusting a grinding or noisy started will involve trying
different shims between the starter and engine. (1% of
starters need this fix)
Cleaning the Armature and
Adjusting Clearance
Your Job.
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Complete chapter Questions 1-10 (review) and
1-10 (ASE-style). Page 448
Write on a separate paper and write out the
complete question and your answer. ( do not
write the other answer options).
Complete the chapter worksheet (I will give it
out). You may write on it.
File all items in your note book.
Notebooks will be graded in the future.