A-6 Electrical Systems Q&A

1. Technician A says that during a battery capacity test the voltage should not go below 9.6 volts at 70F. Technician B says a battery’s voltage reading should increase as temperature decreases. Who is correct?
A Technician A
B Technician B
C Both A and B
D Neither Technician A or B
Answer A is correct. If the capacity voltage goes below 9.6v at 70 F the battery may need to be replaced. Remeber to the test duration is 15 seconds. Any longer can damage the tool

 

2. Technician A says changing the field current changes the alternators voltage output. Technician B says the control module adjusts voltage regulation by battery temperature and voltage. Who is correct?
A Technician A
B Technician B
C Both A and B
D Neither Technician A or B
Answer C is correct. Both technicians are correct.

 

3. The color of an air bag wire/plug is most likely:
A White
B Black
C Yellow
D Blue
Answer C is correct. Yellow is the correct answer.

 

4. The headlights get brighter as a vehicle is accelerated. Technician A says this could be caused by a high capacity battery. Technician B says this could be caused by high charging system voltage. Who is correct?
A Technician A
B Technician B
C Both A and B
D Neither Technician A or B
Answer B is correct. This is caused by high charging system voltage. An electro-mechanical voltage regulator may get stuck in the closed position providing maximum voltage.

 

5. A vehicles engine will not crank. Technician A says to check the starter circuit first. Technician B says to check the condition of the battery first. Who is correct?
A Technician A
B Technician B
C Both A and B
D Neither Technician A or B
Answer B is correct. Always check the battery first.

 

6. All the lights in a tail light circuit illuminate except one. The most likely cause is:
A An open wire
B An open taillight switch
C A blown fuse
D A burned bulb
Answer D is correct. In a parallel circuit one bulb can go out while the others are unaffected.

 

7. A vehicle has a starting problem. Technician A says to use an ammeter to test for starter current draw. Technician B says worn bushings will cause high resistance. Who is correct?
A Technician A
B Technician B
C Both A and B
D Neither Technician A or B
Answer C is correct. High current draw in a starter circuit may be caused by worn bushings. Use an ammeter to check for current draw.

 

8. If a technician reversed the leads of their digital voltmeter on a 12 volt circuit the readout would show:
A 0.00 volts
B -0.00 volts
C 12.00 volts
D -12.00 volts
Answer D is correct. The answer is -12.00 volts. If the leads are reversed using a digital meter the polarity is changed resulting in a negative voltage reading.

 

9. The hazard and turn signal lights are inoperative in a vehicle. Technician A says that they share the same circuit. Technician B says the vehicle may have a faulty flasher. Who is correct?
A Technician A
B Technician B
C Both A and B
D Neither Technician A or B
Answer C is correct. Both technicians are correct. This indicates the use of a combination flasher.

 

10. Technician A says if a dome light keeps blowing fuses to check for a short to ground. Technician B says resistance in a circuit increases current flow.
Who is correct?
A Technician A
B Technician B
C Both A and B
D Neither Technician A or B
Answer A is correct. When a circuit repeatedly blows fuses check for a short.

 

11. A vehicles engine is slow cranking. The battery is in good condition. Technician A says to perform a voltage drop test on the starter circuit. Technician B says voltage must be present in order to perform this test. Who is correct?
A. Technician A
B. Technician B
C. Both Technician A and B
D. Neither Technician A or B
Answer C is correct. Troubleshoot the cables, connections, and the solenoid in the starter circuit using voltage drop testing.

 

12. The electrical symbol above is a:
A. Resister
B. Capacitor
C. Inductor
D. Diode
Answer D is correct. Diodes keep current flowing in one direction and can protect a circuit.

 

13. An alternator suffers from low voltage output. When full-fielded the alternator outputs maximum voltage. The most likely part to be at fault is a:
A. Burned Diode
B. Worn Alternator Brush
C. Faulty Regulator
D. Faulty Rectifier Bridge
Answer C is correct. Full-fielding an alternator bypasses the regulator resulting in maximum voltage output. This is a great way to test for a faulty internal regulator.

 

14. Technician A says a fully charged lead acid automotive battery has a specific gravity of 1.265 at 80° F. Technician B says the specific gravity reading is effected by temperature. Who is correct?
A. Technician A
B. Technician B
C. Both Technician A and B
D. Neither Technician A or B
Answer C is correct. Both technicians are correct.

 

15. A vehicles A/C blower motor works only in the high position. Technician A says to check the blower motor resistor. Technician B says this is most likely a loose ground connection.
A. Technician A
B. Technician B
C. Both Technician A and B
D. Neither Technician A or B
Answer A is correct. A blower motor resistor uses resistance to control blower motor speeds.

 

16. Which solder should be used when repairing an automotive electrical connection.
A. Rosin Core
B. Silver
C. Zinc
D. Acid Core
Answer A is correct. Rosin core solder is non-corrosive.

 

17. The cruise control of a vehicle is inoperative. Technician A says the this may be caused by a faulty control module. Technician B says this may be caused by a faulty brake switch. Who is correct?
A. Technician A
B. Technician B
C. Both Technician A and B
D. Neither Technician A or B
Answer C is correct. Both technicians are correct.

 

18. Technician A says voltage limiter is used in an instrument panel to keep the voltage at 5 volts. Technician B says if the limiter is faulty it may result in high gauge readings. Who is correct?
A. Technician A
B. Technician B
C. Both Technician A and B
D. Neither Technician A or B
Answer C is correct. Both technicians are correct.

 

19. The display of the multimeter indicates:
A. .016 Ohms
B. .016 Volts
C. 16 Ohms
D. 16 Volts
Answer C is correct. The multimeter indicates 16 Ohms.

 

20. The windshield wipers on a vehicle are slow and dragging across the windshield. Technician A says this could be an open circuit at the motors ground. Technician B says the wiper linkage may be binding. Who is correct?
A. Technician A
B. Technician B
C. Both Technician A and B
D. Neither Technician A or B
Answer B is correct. Binding linkage will cause the wipers to drag.

 

21. A vehicles alarm keeps setting off on its own. Technician A says this could be a faulty courtesy light switch. Technician B says the alarm systems control module uses current sensitive switches. Who is correct?
A. Technician A
B. Technician B
C. Both Technician A and B
D. Neither Technician A or B
Answer C is correct. Sensors used by alarm systems include door, trunk, and hood switches. The control module senses any changes in the vehicles electrical system like an attempt to open a door or start the engine. Proximity sensors are used to sense a parameter around the vehicle setting the alarm if someone enters.
 
 
22. The electrical symbol above is :
A. a variable resister
B. a capacitor.
C. an inductor.
D. none of these.
Answer A is correct. A variable resistor allows for adjustment and change in resistance between two points in a circuit.

 

23. Two technicians are discussing a battery that continues to die overnight even after it has been charged the day before. Technician A says this could be caused by a faulty alternator. Technician B says this could be caused by the vehicles dome light. Who is correct?
A. Technician A
B. Technician B
C. Both Technician A and B
D. Neither Technician A or B
Answer C is correct. Both technicians are correct.

 

24. The lamp in the glove box is inoperative. The test light is illuminated at point C with the glove box open and the switch closed. The most likely cause of this problem is:
A. a burned bulb filament.
B. an open between the switch and the ground.
C. excessive resistance at point B of the circuit.
D. a short to ground at point D of the circuit.
Answer B is correct. This is the most likely. If the circuit is open between the switch and ground, the bulb will not illuminate.

 

25. An alternator output test is being performed on a vehicle. Technician A says for maximum alternator output the engine must be revved to a high idle of 2000 RPM. Technician B say for maximum output turn the vehicles accessories on during the test. Who is correct?
A. Technician A
B. Technician B
C. Both Technician A and B
D. Neither Technician A or B
Answer C is wrong. Both technicians are correct.

This post was written by: Martin Hand

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Martin Hand

About Martin Hand

ASE Certified L1 Advanced Mastertech. Martin Hand has over 15 years experience in Asian and European Import Auto Repair. Specializing in electrical diagnosis, engine performance, AT/MT transmission repair/rebuild. Martin is also pursuing a degree in Computers Science & Information Systems starting at Portland Community College while he plans to transfer to OIT. Certified in Java application level programming, experienced with other languages such as PHP, Ruby, JavaScript and Swift. Martin has future plans of automotive diagnostic software development.