ASE Electrical and Electronic Systems 2 — Questions and Answers
Question 1: During cranking, a voltage drop test across the positive battery cable (battery post to starter terminal) should generally read no more than:
- 0.5 volt (Correct answer)
- 2.0 volts
- 4.5 volts
- 9.6 volts
Correct answer: 0.5 volt
Most manufacturers allow about 0.5 V maximum drop on the starter's positive cable circuit under load.
Question 2: After all modules go to sleep, what is a typical maximum acceptable key-off parasitic draw on most late-model vehicles?
- About 500 mA
- About 50 mA or less (Correct answer)
- About 2 amps
- About 1.5 amps
Correct answer: About 50 mA or less
Most vehicles specify roughly 50 mA or less once modules have entered sleep mode.
Question 3: A 12-volt circuit has a total resistance of 4 ohms. How much current flows?
- 48 amps
- 0.33 amp
- 3 amps (Correct answer)
- 16 amps
Correct answer: 3 amps
Using Ohm's law, I = E / R, so 12 V / 4 Ω = 3 A.
Question 4: A voltmeter connected across an open switch in a 12-volt series lamp circuit will read:
- 0 volts
- About 6 volts
- Battery voltage (about 12 volts) (Correct answer)
- A value that depends only on lamp wattage
Correct answer: Battery voltage (about 12 volts)
With no current flow, there is no drop across the lamp, so the full source voltage appears across the open.
Question 5: When a good silicon diode is tested with a DMM on the diode-check function, the expected readings are:
- OL in both directions
- About 0.5–0.7 V one direction and OL in the other (Correct answer)
- 0.00 V in both directions
- About 12 V forward and 0.6 V reverse
Correct answer: About 0.5–0.7 V one direction and OL in the other
A good diode conducts in one direction (about 0.5–0.7 V drop) and blocks in the other (OL).
Question 6: An AC ripple reading above about 0.5 volt AC at the alternator output most likely indicates:
- A faulty voltage regulator only
- A failed rectifier diode or stator winding (Correct answer)
- A loose serpentine belt
- An overcharged battery
Correct answer: A failed rectifier diode or stator winding
Excessive AC ripple means the rectifier is not converting AC to DC properly, typically from a bad diode or stator.
Question 7: On a standard ISO mini relay, terminals 85 and 86 are connected to:
- The high-current load circuit
- The relay control coil (Correct answer)
- The normally closed contact
- The battery feed to the load
Correct answer: The relay control coil
Terminals 85 and 86 are the coil (control) side, while 30 and 87 are the switched load contacts.
ASE Electrical and Electronic Systems 2
During cranking, a voltage drop test across the positive battery cable (battery post to starter terminal) should generally read no more than: