CH17 HEAVY DUTY STARTING SYSTEMS AND CIRCUITS -
Q&A UPDATED ACTUAL QUESTIONS AND CORRECT
ANSWERS
Question:
1. 1. Which of the following is the correct sequence for current flow thru a series-type starter motor?
A. Field poles, brush, commutator, armature, brush
B. Armature, brush, commutator, brush, field poles
C. Brush, armature, commutator, brush, field poles
D. Field poles, armature, brush, commutator, brush
Answer:
C. Brush, armature, commutator, brush, field poles, p382
Question:
2. 2. What test instrument is best used to check for resistance as a starter circuit when cranking?
A. AVR
B. Ohmmeter
C. Voltmeter
D. Test light
Answer:
C. Voltmeter, p400
Question:
3. 3. Consider a starter has a "chattering" solenoid when attempting to crank the engine. If sufficient
battery current is available to the solenoid, which of the following is most likely defective?
A. Hold-in winding
B. Pull-in winding
C. Misadjusted pinion clearance
D. The starter relay
Answer:
C. Misadjusted pinion clearance, p396
Question:
4. 4. A starting motor should not be operated for longer than:
A. 15 seconds
B. 30 seconds
C. 1 minute
D. 2 minutes
Answer:
B. 30 seconds, p383
,Question:
5. 5. Which of the following changes takes place to the electrical properties of a starter circuit as the flow
of amperage increases?
A. Increase in voltage through the circuit
B. Increase in resistance through the circuit
C. Decrease in resistance thru the circuit
D. Increased CEMF thru the circuit
Answer:
C. Decrease in resistance thru the circuit, p383
Question:
6. When battery voltage is low, the starter uses
Answer:
Even more amperage to rotate. Starters use any combination of voltage and amperage to produce the
necessary power for cranking torque, which is measured in watts. Watts = volts x amperage
Question:
7. By increasing amperage drawn from batteries, in turn,
Answer:
Increases batteries' internal resistance. Increased resistance causes available battery voltage to drop even
further, which in turn increases the amperage needed to rotate the starter.
Question:
8. 6. Consider performing three consecutive starter ranking cycles of 30 seconds with two-minute rest
intervals between cycles. If batteries are correctly sized and no defects are present in the starter circuit or
engine, battery voltage during cranking should not fall below:
A. 7.5 volts
B. 9.6 volts
C. 10.5 volts
D. 12.4 volts
Answer:
C. 10.5 volts, p384
Question:
9. 7. Which of the following reasons best explains why gear reduction starters draw less current than
direct-drive starters?
A. Gear reduction starters produce more torque.
B. Gear reduction starters have more resistance in armature and field windings.
C. Gear reduction starters rotate faster.
D. Gear reduction starters have less capacity to absorb heat from extended cranking periods.
Answer:
C. Gear reduction starters rotate faster, p378
, Question:
10. 8. When testing the starting system on a vehicle with a six-cylinder 855-cubic inch Diesel engine, you
find that the engine cranks slowly. The starter current draw is 90 amps, and the battery voltage during
cranking is 12.1 volts. what should you do next?
A. Check the starter circuit for resistances
B. Load test the battery
C. Replace the starter
D. Inspect the engine for seizure
Answer:
A. Check the starter circuit for resistances, p396-97
Question:
11. 9. What is the maximum voltage drop allowed when performing a starter cable voltage drop test on a
12-volt system?
A. 0.2 volt - 0.8 volt for the entire circuit
B. 0.5 volt for each connection
C. 1.0 volt for entire circuit
D. 0.5 volt - 0.8 volt for each cable
Answer:
A. 0.2 volt - 0.8 volt for the entire circuit, p399
Question:
12. 10. What is the most likely cause for a failure of an engine to crank, but the starting motor turns?
A. Bent armature
B. Defective solenoid
C. Defective starter drive mechanism
D. An open hold-in winding on the solenoid
Answer:
B. Defective solenoid, p397
Question:
13. 1. Technician A says dozens of electric motors are found in heavy vehicles operating a variety of
devices from electric seats, fuel and coolant pumps, fan blower motors, and even instrument gauges.
Technician B says the largest of all these electric motors is the starter motor. Who is correct?
A. Technician A
B. Technician B
C. Both Technician A and Technician B
D. Neither Technician A nor Technician B
Answer:
C. Both Technician A and Technician B, p377
Q&A UPDATED ACTUAL QUESTIONS AND CORRECT
ANSWERS
Question:
1. 1. Which of the following is the correct sequence for current flow thru a series-type starter motor?
A. Field poles, brush, commutator, armature, brush
B. Armature, brush, commutator, brush, field poles
C. Brush, armature, commutator, brush, field poles
D. Field poles, armature, brush, commutator, brush
Answer:
C. Brush, armature, commutator, brush, field poles, p382
Question:
2. 2. What test instrument is best used to check for resistance as a starter circuit when cranking?
A. AVR
B. Ohmmeter
C. Voltmeter
D. Test light
Answer:
C. Voltmeter, p400
Question:
3. 3. Consider a starter has a "chattering" solenoid when attempting to crank the engine. If sufficient
battery current is available to the solenoid, which of the following is most likely defective?
A. Hold-in winding
B. Pull-in winding
C. Misadjusted pinion clearance
D. The starter relay
Answer:
C. Misadjusted pinion clearance, p396
Question:
4. 4. A starting motor should not be operated for longer than:
A. 15 seconds
B. 30 seconds
C. 1 minute
D. 2 minutes
Answer:
B. 30 seconds, p383
,Question:
5. 5. Which of the following changes takes place to the electrical properties of a starter circuit as the flow
of amperage increases?
A. Increase in voltage through the circuit
B. Increase in resistance through the circuit
C. Decrease in resistance thru the circuit
D. Increased CEMF thru the circuit
Answer:
C. Decrease in resistance thru the circuit, p383
Question:
6. When battery voltage is low, the starter uses
Answer:
Even more amperage to rotate. Starters use any combination of voltage and amperage to produce the
necessary power for cranking torque, which is measured in watts. Watts = volts x amperage
Question:
7. By increasing amperage drawn from batteries, in turn,
Answer:
Increases batteries' internal resistance. Increased resistance causes available battery voltage to drop even
further, which in turn increases the amperage needed to rotate the starter.
Question:
8. 6. Consider performing three consecutive starter ranking cycles of 30 seconds with two-minute rest
intervals between cycles. If batteries are correctly sized and no defects are present in the starter circuit or
engine, battery voltage during cranking should not fall below:
A. 7.5 volts
B. 9.6 volts
C. 10.5 volts
D. 12.4 volts
Answer:
C. 10.5 volts, p384
Question:
9. 7. Which of the following reasons best explains why gear reduction starters draw less current than
direct-drive starters?
A. Gear reduction starters produce more torque.
B. Gear reduction starters have more resistance in armature and field windings.
C. Gear reduction starters rotate faster.
D. Gear reduction starters have less capacity to absorb heat from extended cranking periods.
Answer:
C. Gear reduction starters rotate faster, p378
, Question:
10. 8. When testing the starting system on a vehicle with a six-cylinder 855-cubic inch Diesel engine, you
find that the engine cranks slowly. The starter current draw is 90 amps, and the battery voltage during
cranking is 12.1 volts. what should you do next?
A. Check the starter circuit for resistances
B. Load test the battery
C. Replace the starter
D. Inspect the engine for seizure
Answer:
A. Check the starter circuit for resistances, p396-97
Question:
11. 9. What is the maximum voltage drop allowed when performing a starter cable voltage drop test on a
12-volt system?
A. 0.2 volt - 0.8 volt for the entire circuit
B. 0.5 volt for each connection
C. 1.0 volt for entire circuit
D. 0.5 volt - 0.8 volt for each cable
Answer:
A. 0.2 volt - 0.8 volt for the entire circuit, p399
Question:
12. 10. What is the most likely cause for a failure of an engine to crank, but the starting motor turns?
A. Bent armature
B. Defective solenoid
C. Defective starter drive mechanism
D. An open hold-in winding on the solenoid
Answer:
B. Defective solenoid, p397
Question:
13. 1. Technician A says dozens of electric motors are found in heavy vehicles operating a variety of
devices from electric seats, fuel and coolant pumps, fan blower motors, and even instrument gauges.
Technician B says the largest of all these electric motors is the starter motor. Who is correct?
A. Technician A
B. Technician B
C. Both Technician A and Technician B
D. Neither Technician A nor Technician B
Answer:
C. Both Technician A and Technician B, p377
