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Chapter 9
End of Chapter Review Questions Answer Key
1. What is the function of the control circuit in a truck cranking circuit?
2. What component prevents a starter motor from being turned by the engine at speeds
that could damage the motor?
3. If cranking current is tested to be excessively high, which of the following is the most
likely cause of the problem?
4. Which of the following best describes the operating principle of a typical truck starter
motor?
5. When will output torque be greatest in a truck starter motor?
6. What is the usual maximum permitted voltage drop through the insulated side of the
starter circuit?
7. What is the usual maximum permitted voltage drop through the ground side of the
starter circuit?
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8. What device is used on some cranking circuits to prevent starter motor operation if the
voltage drops below 9.6 volts?
9. What is the reason for using a planetary gearset in modern starters such as the Remy
39MT?
10. Which cranking system component is common to both the control circuit and the
high-current starter circuit?
11. When checking voltage drop through a negative battery clamp, where should the
positive voltmeter lead be placed?
12. When growler testing an armature, if a steel strip vibrates when placed on the
armature, which of the following conditions is indicated?
13. Technician A says that a voltage drop of 0.4 volt measured over a battery terminal and
post indicates a high-resistance connection. Technician B says that ground circuit
specifications for voltage drops tend to be higher than on insulated circuits. Who is
correct?
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14. Technician A says that a starter relay is a magnetic switch. Technician B says that the
control circuit in a starter relay conducts the starter motor current load. Who is
correct?
15. Which of the following produces the stationary magnetic fields in a typical truck
starter motor?
16. Technician A says that most heavy-duty starter motors are series wound. Technician
B says that most heavy-duty starters produce peak torque when driven at the highest
rpm. Who is correct?
17. What has to be adjusted to change the pinion clearance specification in a 42MT starter
motor?
18. Technician A uses a spring tension gauge to set the starter motor pinion clearance
specification. Technician B uses thickness gauges to measure pinion clearance. Who
is correct?
19. What is the function of a neutral safety switch in the cranking circuit?
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20. Technician A says that the sun gear pinion is integral with the armature shaft on a
Remy 39MT starter motor. Technician B says that the ring gear is the output member
of the planetary gearset on a 39MT starter motor. Who is correct?