ASE Mechanical & Electrical Components 2 — Questions and Answers
Question 1: A vehicle's battery reads 12.2 volts at rest. What is its approximate state of charge?
- 50% (Correct answer)
- 75%
- 100%
- 25%
Correct answer: 50%
A resting voltage of 12.2V corresponds to roughly a 50% state of charge.
Question 2: Which tool is best for measuring excessive resistance (voltage drop) in a starter cable?
- Voltmeter set across the cable while cranking (Correct answer)
- Test light
- Compression gauge
- Vacuum gauge
Correct answer: Voltmeter set across the cable while cranking
A voltage-drop test uses a voltmeter across a circuit under load to reveal hidden resistance.
Question 3: A whining noise from the alternator that rises with engine speed most likely indicates:
- Worn bearings (Correct answer)
- A dead battery
- A blown fuse
- Loose battery terminals
Correct answer: Worn bearings
Worn alternator bearings produce a whine or growl that tracks engine RPM.
Question 4: What does a parasitic draw test measure?
- Current drawn with the ignition off (Correct answer)
- Charging voltage at idle
- Starter amperage
- Belt tension
Correct answer: Current drawn with the ignition off
A parasitic draw test checks for current leaking from the battery while everything is off.
Question 5: Which component converts the alternator's AC output into DC for the vehicle?
- Rectifier diodes (Correct answer)
- Voltage regulator
- Rotor
- Slip rings
Correct answer: Rectifier diodes
The diode rectifier bridge converts the stator's AC into usable DC.
Question 6: A starter that clicks but does not crank, with a good battery, most likely has:
- A faulty starter solenoid or high resistance (Correct answer)
- A blown headlight fuse
- A bad alternator
- Low coolant
Correct answer: A faulty starter solenoid or high resistance
A single click usually means the solenoid engages but the motor cannot turn, often from resistance or a bad solenoid.
Question 7: When using a digital multimeter to check a fuse in-circuit, you should set it to:
- Voltage and check for drop across the fuse (Correct answer)
- Resistance with circuit powered
- Frequency
- Temperature
Correct answer: Voltage and check for drop across the fuse
With power on, a good fuse shows near 0V drop while a blown fuse shows full voltage across it.
ASE Mechanical & Electrical Components 2
A vehicle's battery reads 12.2 volts at rest.
What is its approximate state of charge?