CAUTION
CAUTION
Before performing test 5, the voltmeter scale
Do not operate the starting motor for an
selector switch must be set to a scale position above
extended length of time, as it can be severely
battery voltage to prevent damage to the voltmeter.
damaged by overheating. Operate the starter for a
maximum of 30 seconds, and then allow it to cool
TEST 6.--With the voltmeter leads connected
for 2 minutes before you resume cranking.
between the battery's negative post and the ground
terminal of the solenoid, attempt to crank the engine.
TEST 1.--With the voltmeter leads connected
Voltage drop should not exceed 0.1 volt. If the drop
between the battery's positive post and the starting
exceeds 0.1 volt, the high resistance is in the solenoid
motor terminal, attempt to crank the engine. Voltage
ground circuit (wiring, connections, neutral safety
reading (drop) should not exceed 0.5 volt. If the drop
switch, or starter lockout devices).
exceeds 0.5 volt, the high resistance is in the starting
If the results of tests 5 and 6 on a solenoid-operated,
system rather than the starting motor. If the drop does
overrunning-clutch starter system are within limits and
not exceed 0.5 volt, perform test 4 to determine if the
the solenoid does not operate, the starter must be
high resistance is in the starting motor or in the starting
removed for further testing. The test procedure and the
motor ground circuit.
maximum allowable voltage drop is the same for the
TEST 2.--With the voltmeter leads connected
relay-operated starter system.
between the battery's positive post and the battery
Q6-29. What is the purpose of the starter motor?
terminal of the solenoid, attempt to crank the engine.
1. To rotate the cam shaft
Voltage drop should not exceed 0.1 volt. If the drop
2. To convert ac alternator output to dc cur-
exceeds 0.1 volt, the high resistance is in either the
rent for engine cranking
battery cable connections or the battery cable between
3. To change electrical energy to mechanical
these test points.
energy
TEST 3.--With the voltmeter leads connected
4. To change mechanical energy to electrical
between the battery's positive post and the starting
energy
motor terminal of the solenoid, attempt to crank the
Q6-30. Which of the following methods does a starter
engine. Voltage drop should not exceed 0.5 volt. If the
motor use to transmit its cranking power to
drop should exceed 0.5, the high resistance is in the
the engine?
solenoid. Either its contacts are burned or they are not
1. Electromotive force
closing.
2. Electromechanical force
3. Gear compensation
TEST 4.--With the voltmeter leads connected
4. Gear reduction
between the battery's negative post and the starting
motor frame, attempt to crank the engine. Voltage drop
Q6-31. Which of the following components is
should not exceed 0.1 volt. If the drop exceeds 0.1 volt,
designed to prevent the starter motor from
the high resistance is in the ground circuit between the
being driven by the engine after the engine
battery and the starting motor (ground cable, cable
has been started?
connections, or starter mountings). If the voltage drop
1. The starter lock-out relay
does not exceed 0.1 volt, the starter must be removed
2. The overrunning clutch
for further testing.
3. The overspeed clutch
4. The kick-out gears
TEST 5.--With the voltmeter leads connected
Q6-32. On starters that have overrunning clutch
between the battery's negative post and the solenoid
drives, what purpose does a solenoid serve?
switch terminal, attempt to crank the engine. Available
1. To prevent excessive current flow to the
voltage should not be less than battery voltage. If a
starter
reading lower than this is obtained, the high resistance
2. To shift the starter pinion into engagement
is in the starter switch circuit (neutral safety switch,
with the ring gear
connections, or wiring). If correct voltage is indicated
3. To boost current flow for turning the starter.
and the solenoid does not operate, perform test 6. If the
4. To disengage the starter pinion from the
solenoid is grounded internally, the starter must be
ring gear
removed for further testing.
6-60
