ASE (Entry level technician prep) - Electrical A6

During an output test using the full-field method, a 100-ampere alternator with an integral regulator produces 60 amperes. The cause of the low alternator output could be: A)a shortened diode in the alternator B)a broken brush lead wire in the alternator. C)an open circuit in the voltage regulator. D)a defective alternator capacitor.

Answer A is correct! A shorted diode in a gneerator will typically cause the amperage output to be about one-third less than normal.

A car comes in the shop with a no crank and no sound from the solenoid complaint. The technician turns on the headlights and moves the ignition to the "start" position. The brightness of the headlights stays the same and the complaint is verified. All of the following could be the cause of the problem EXCEPT: A) an undercharged battery. B) a faulty clutch switch. C) a bad starter. D) an open in the starter circuit.

Answer A is correct! An undercharged battery probably would not allow the headlights to be bright in the first place. Also, if the starter circuit were okay, the light would get very dim when the ingition was turned to start. This would happen even though the starter and solenoid could not work because of the low voltage.

When performing a battery hydrometer test: A) if the battery temperature is 0 deg F (-17.7 deg C), 0.050 should be subtracted from the hydrometer reading. B) if the battery temperature is 120 deg F (48.9 deg C), 0.020 should be subtracted from the hydromter reading. C) the maximum variation in cell hydrometer readings is 0.050 specific gravity points. D) The battery is fully charged if all cell hydrometer readings exceed 1.225

Answer A is correct! The hydrometer measures the specific gravity of the battery's electrolyte. This measurement gives an indication of the battery's state of charge. The reading is quite simple to take, but it must be adjusted according to the temperature. The base temperature for this reading is 80 deg F. When the temperature is below that, 0.004 should be subtracted from the measurement for every ten degrees below 80.

During a starter current draw test, the current draw is more than specified, and the cranking speed and battery voltages are less than specified. The cause of this problem may be: A) worn bushings in the starter motor. B) high resistance in the field windings. C) high resistance in the battery positive cable. D) a burned solenoid disc and terminals.

Answer A is correct! The slower a motor turns, the more amperage it will draw. Therefore the only answer that is correct is A. Worn bushings will cause the motor to turn slower than normal and will cause high current draw.

All of these statements about rear defoggers are true EXCEPT: A) many rear defoggers are controlled by a timer. B)when the defogger is on, 9.5 volts are supplied to the grid. C)each track in the grid is parallel to the other tracks. D) in many defogger circuits, the timer energizes the defogger relay.

Answer B is correct! All are true except B, which incorrectly states the amount of voltage supplied to the grid.

All of the following statements about using a lab scope for diagnosis are correct EXCEPT: A) An upward movement of the trace means the voltage has increased and a downward movement means the voltage has decreased. B)The size and clarity of the trace is dependent on the cleanness of the connection and the component or circuit being tested. C)A flat waveform means the voltage is staying at that level. D)As the trace moves across the screen of the oscilloscope, time is represented.

Answer B is correct! An oscilloscope converts electrical signals into a visual image representing voltage chanes over a specific period of time. B is a false statement

All the instrument cluster bulbs intermittently go on and off while driving the vehicle. The most likely cause of this problem could be: A)one loose instrument cluster bulb in the printed circuit board. B)an intermittent open in the instrument cluster ground. C)a grounded circuit between the rheostat and the instrument cluster bulbs. D)a defective circuit breaker in the instrument light circuit.

Answer B is correct! Answer A presents a problem that would affect only one bulb, not all of the bulbs and is therefore a wrong answer. C and D both suggest a problem that would not tend to be intermittent. Both of these problems would cause the bulbs to be off continuously.

All of the following could cause a power seat to move very slowly or not work at all EXCEPT: A) poor ground connections. B)an open switch. C)binding linkages. D)a faulty motor.

Answer B is correct! It is the job of the switch to close the circuit. B is the correc tanswer because it would not be a likely cause for both problems.

In a courtesty light circuit with insulated side door jamb switches, the courtesy lights are completely inoperative. The courtesy light fuse is not blown. The cause of the problem could be: A) an open circuit in one door jamb switch. B)an open circuit between the fuse and the door jamb switches. C)a grounded circuit in one of the door jamb switches. D)a grounded circuit between the door jamb switches and the bulbs.

Answer B is correct! None of the courtesy lights work. The problem must be in that part of the circuit that affects the entire circuit.

A customer complains that the engine will not turn over. Technician A says to first check if the engine will turn over by turning the crankshaft pulley nut. Technician B says to check the battery condition first. Who is right? A) A only B) B only C) Both A and B D) Neither A nor B

Answer B is correct! Normally, there are other indications for a seized engine being the caused of a no-crank condition. Although Technician A is correct by wanting to verify that the engine is or is not seized by rotating It with a large wrench, this should not be done first. The first thing to do when facing a no-crank situation is to check the battery.

All of the following could cause premature failure of a composite bulb EXCEPT: A)high charging voltage. B)excessive resistance in the bulb ground circuit. C)improper bulb handling. D)cracked lamp cover or housing.

Answer B is correct! Three of the answers (A, C, and D) correctly state conditions that would cause premature composite bulb failure. A high charging rate will cause the bulbs to burn brighter and hotter than normal, leading to premature failure.

All of the following can cause the vehicle's warning lights not to work EXCEPT: A)a burned-out blb. B)a short to ground in the sending unit circuit. C)an open in the sending unit circuit. D)a defective sending unit.

Answer B is correct! Warning lights are simple circuits. Power is supplied to the light at all times, and the sending unit switches to open or close the circuit by completing the path to ground. When satisfactory conditions are met, the circuit is open and the bulb is off. Any problem tha topens the circuit will keep the light off at all times.

The battery voltage is disconnected from the electrical system in a vehicle with many on-board computers. This procedure may cause: A) damage to all the computers. B) the engine to not start. C) erasure of the computers' adaptive memories. D) voltage surges in the electrical system.

Answer C is correct! Correctly disconnecting the battery on late-model vehicles will not cause any problems to the computer or the vehicle itself. The only thing that will happen is that item held in memory by the computers and accessories will disappear.

The cigar lighter requires repeated fuse replacements. The cause of this problem could be: A) high resistance in the lighter element. B)a high resistance connector on the cigar lighter. C)a shorted lighter element D) a grounded wire between the lighter and the chassis.

Answer C is correct! High resistance always decreases current flow, and low current will never cause a fuse to blow.

What type of problem is indicated by a lower than normal amperage reading when a circuit is activated? A ) An open B) A short C ) High resistance in the circuit D) A blown fuse

Answer C is correct! Lower amperage is always caused by higher than normal resistance somewhere in the circuit. An open circuit has no current flow and therefore A is not correct. A short would cause higher than normal current flow. A blown fuse is caused by a short, which would not cause lower than normal current flow through the circuit.

When diagnosing and testing a rear defogger circuit: A)the voltage drop from the ground side of the grid to an engine ground should not exceed one folt. B)a 12V test light should be illuminated at half brilliance in any place on a grid track. C) if a 12V test light is not illuminated on part of a grid track, the track is open. D) a 12V test light should become brighter as it is moved to the ground side of the track.

Answer C is correct! The brilliance of the test light ddecreases as It moves towards the negative or ground side of the grid.

Which of the following is the LEAST likely cause for an inoperative retractable headlight door? A)A defective headlight motor B) Loose or broken vacuum lines C)A poor headlamp ground D)A faulty limit switch

Answer C is correct! The least likely cause of the problem is a poor headlight ground. This problem would affect the brilliance of the headlight, not the performance of the retractable door. The other answers or statements are correct.

A six-way power seat moves vertically at the front and rear, but there is no horizontal seat movement in the figure. All of these defects may be the cause of the problem EXCEPT: A)a newspaper jammed in the seat track mechanism. B)an open circuit between the switch and the horizontal motor. C)an open circuit in the circuit from the switch assembly to ground. D)burned contacts in the horizontal seat switch.

Answer C is correct! The only choice that would not affect horizontal movement is C. An open in the ground circuit would affect the total operation of the seat. A jammed seat track, an open between the switch and the horizontal motor, and a burned contact in the horizontal seat switch would all hinder or prevent horizontal movement.

During an initial display on a digital instrument cluster, some of the segments in the fuel gauge are not illuminated. All the other segments are illuminated properly. To correct this problem: A) the fuel gauge segments should be replaced. B)test the fuel gauge circuit from the gauge to the sending unit. C)replace the digital instrument display. D)test the instrument voltage limiter.

Answer C is correct! The problem stated in this question is that some of the segments of the fuel gauge in a digital instrument cluster are not illuminating. The question asked for the way to fix the problem. Th eonly way to fix the problem of the missing gauge segments is to replace the entire instrument cluster.

All of these statements about halogen headlight bulb replacements are true EXCEPT: A) handle the halogen bulb only by the base. B)do not drop or scratch the bulb. C)change the bulb with the headlights on. D)keep moisture away from the bulb.

Answer C is correct! When replacing a halogen lightbulb always turn off the headlights and allow the bulb to cool. Keep moisture away from the bulb, and handle the bulb by its base. Do not scratch or drop the bulb. Coat the terminals in dielectric grease to minimize corrosion.

A circuit breaker is removed from a functioning power seat circuit, and an ohm-meter is connected to the circuit breaker terminals. Technician A says the ohmmeter should provide an infinite reading if the circuit breaker is satisfactory. Technician B says the ohmmeter current may cause the circuit breaker to open. Who is right? A) A only B)B only C)Both A and B D)Neither A nor B

Answer D is correct! An infinite reading on an ohmmeter indicates there is an open. A good circuit breaker is closed until high current flows through it, then it is open. A good circuit breaker will have zero resistance.

Which of the following is the LEAST likely cause for an inoperative windshield washer system, if the windshield wipers work properly? A)Low fluid levels B) Defective switch C)Defective pump D)Blown fuse

Answer D is correct! Because the windshield wipers function normally, you can assume that the fuse for the circuit is okay. It is unlikely that the vehicle will have a separate fuse for the washer system; therefore D is not a likely cause of the problem.

All of these statements about remote keyless entry systems are true EXCEPT: A) on many systems, the interior lights are illuminated when the unlock button on the remote control is pressed. B)when the interior lights are turned on by the remote keyless entry system, these lights go off after approximately one minute. C)when interior lights are turned on by the remote keyless entry system, these lights go off when the ignition switch is turned on. D)the remote control unlocks the doors when the remote transmitter is 100 yars (91 meter) from the vehicle.

Answer D is correct! Most remote control units need to be fairly close to activate or deactivate the door locks. 100 yards is quite far away. The other statements are true.

The charging system voltage on a vehicle is 16.2V. This condition may cause all the following problems EXCEPT: A)an overcharged battery. B)burned-out electrical components. C)electrolyte gassing in the battery. D)reduced headlight brilliance

Answer D is correct! Obviously 16.2 volts from the charging station is too much for a 12-volt battery. Answer A is correct. B is also correct - the high voltage could cause damage to electronic components. With an overcharged battery, gassing does increase, so C is also correct.

A radio has a whining noise that increases with engine speed. When the alternator field wire is disconnected, the noise stops. All of these defects may be the cause of the problem EXCEPT: A) a defective stator. B) a defective diode. C)a defective capacitor. D)an open field winding.

Answer D is correct! This problem would tend to decrease the chance of radio noise because the alternator (a major source of noise) would not work. A defective alternator will usually cause a whining noise.

The battery discharges overnight continually. Once the battery is replaced, a drain test is done. The multimeter reading below indicates a parasitic drain. Which of these statements is true? A2 0.035 A. 35A of current is indicated B. This number is unacceptable C. 35mA of current is indicated D. Both A or B could be right

C. 35mA of current is indicated was correct. This reading shows 35mA of current. As a general rule of thumb, it's acceptable to have up to a 50mA parasitic drain. A is incorrect because it shows 35mA which is far less than 35A

What would be the least likely reason you experience a dim headlight out of these options? A. Low output from the alternator B. Headlight connector is corroded C. Headlight wiring has high resistance D. Broken or damaged headlight assembly

Correct answer A - All of these reasons could be the cause of a dim headlight but A is the least likely. More common symptoms of a failing alternator are a dead battery, engine stalling, odd noises and the service engine light

Two technicians discuss the state of charge of a battery. Technician A states that a specified gravity of 1.225 at 80F shows the battery has a state of charge at about 75%. Technician B states that it's possible to use the hydrometer to check the state of charge if you are troubleshooting a maintenance-free battery. Who is correct? A. Technician A B. Technician B C. Both technicians D. Neither technician

Correct answer A - Tech A is correct. The reason Tech B is incorrect is that maintenance free batteries don't contain any openings. This means there is nowhere to check the gravity with the hydrometer.

The doors on a vehicle won't unlock with the remote keyless entry. These could all be the cause EXCEPT: A. Bad passenger door lock motor B. Blown circuit breaker C. Weak transmitter battery D. Interference from a stronger radio transmitter

Correct answer A - The faulty door lock motor would only prevent that door from opening. It has nothing to do with the operation of the other doors. All of these other options might cause the doors to remain locked.

The horn is making a weak sound. Technician A believes the faulty power connection is the reason. Technician B believes the faulty fuse might be the cause. Who is correct? A. Technician A B. Technician B C. Both technicians D. Neither technician

Correct answer A - When the horn is weak, the current is too low. Poor electrical connections could be the cause. When the fuse is blown, the horn doesn't sound at all.

The rear defogger grid is being tested. Technician A believes that the voltmeter should decrease its reading while probing a grid line as it gets close to the ground bus bar. Technician B believes that when the voltmeter reads 12 volts at both ends of the grid line, it means there's an open in the grid line. Who is correct? A. Technician A B. Technician B C. Both technicians D. Neither technician

Correct answer A - You will want to check for a loose ground if the test light remains bright at both ends. If there is an open in the grid line, the test light won't get dimmer. It should remain the same brightness until it gets to the other side of the open. Then, it will go out.

Technician A states that a loose serpentine alternative drive belt might lead to overcharging. Technician B states that undersized wiring between the battery and alternator might cause undercharging. Who is correct? A. Technician A B. Technician B C. Both technicians D. Neither technician

Correct answer B - Tech A is incorrect because undercharging is the result of a slipping belt. Tech B is right because the undersize wiring leads to undercharging. This is caused by higher resistance.

What tool can check continuity in wires that carry digital signals? A. Voltmeter B. Logic probe C. Analog meter D. Megger meter

Correct answer B - The logic probe is the only tool you could use to measure digital signals. The voltmeter measures electrical potential difference between two points in an electric circuit. An analog meter measures voltage, current, and resistance. The megger meter measures insulation resistance of electrical system

Which of these is true about a series circuit? A. Lowest resistance contains the most current B. Lowest resistance contains the highest voltage drop C. Highest resistance contains the highest voltage drop D. Highest resistance contains the most current

Correct answer C - According to Kirchhoff's Voltage Law: Voltage higher before resistance than after, which is the result of total applied voltage not equal at both ends of a single load circuit. The resistance opposes electron flow which results in voltage loss applied to the load. This loss is voltage drop with the voltage consumed as current travels through resistance. If you have higher resistance, you have higher drop.

The power seat system is noisy when operated. All of these might be the cause EXCEPT: A. Lack of lubricant B. Faulty motor C. Bad ground D. Faulty transmission

Correct answer C - All of these could lead to a noisy operation except for a bad ground. This would make the seat operate slowly or disable it completely. It will not lead to noise.

The vehicle sunroof works intermittently. Technician A states that it might be a poor wiring connection. Technician B states that the panel might be binding in the rails. Who is correct? A. Technician A B. Technician B C. Both technicians D. Neither technician

Correct answer C - Both technicians are correct. Corroded or loose connections lead to intermittent trouble. The glass binding in the rails might also lead to an overheating electric motor which would trip the circuit breaker. Once that breaker resets, the panel might begin to work again.

Technician A states that a short circuit to ground in a circuit decreases resistance. Technician B states that a short circuit increases current flow. Who is correct? A. Technician A B. Technician B C. Both technicians D. Neither technician

Correct answer C - Both technicians are correct. There's little or no resistance with a short to ground. It's also true that the current flow increases when resistance decreases.

While discussing an alternator that has zero output, Technician A states that the field circuit might have an open circuit. Technician B states that the fusible link might be open to the alternator from the battery. Who is correct? A. Technician A B. Technician B C. Both technicians D. Neither technician

Correct answer C - Both techs are correct. It's possible that the field circuit might have an open circuit. It's also true that it could be an open fusible link from the battery to the alternator.

The vehicle turn signals begin to flash too slow. Technician A believes that the issue is caused by a faulty flasher. Technician B believes the bulb is an incorrect type. Who is correct? A. Technician A B. Technician B C. Both technicians D. Neither technician

Correct answer C - Both techs are correct. The incorrect wattage and improperly rated flasher could cause the signal to flash incorrectly. Turn on the signal and inspect it to determine the problem.

While performing a starter current draw test, you notice the current draw is more than specified. The battery voltages and cranking speed appear to be less than specified. What is the cause of your problem? A. High resistance in the field windings B. A burned solenoid disc and terminals C. Worn bushings in the starter motor D. High resistance in the battery positive cable

Correct answer C - Both techs are correct. Worn bushes commonly cause a high current draw in the starter circuit. They lead to binding and turning resistance. You also would use the ammeter to check current draw and amperage.

An analog ohmmeter needle won't move when connected to both sides of the rotor. What does this mean about the rotor winding? A. It is grounded B. It is shorted C. It is open D. It is complete

Correct answer C - This ohmmeter is showing infinite resistance or infinity. This is what happens when the needle doesn't move. With the rotor winding shows, the circuit is open.

What solder type is needed for instrument panel wiring repair? A. 60/40 with no flux B. Acid core C. 50/50 with acid paste flux D. Rosin core

Correct answer D - Rosin core is the only solder type to ensure integrity in this repair. It's specified for use on any electric repair. The other options would be unacceptable ways to perform the repair.

When a faulty fuel gauge indicates a full tank, what's the most likely reason? A. Stuck float in the up position B. Open fuse C. Broken gauge D. Wire leading to sending unit ground

Correct answer D - While there could be many causes; this is the most likely as the question indicated. It can also cause other symptoms such as erratic readings and stuck on empty as well. The least common cause would be trouble with the instrument panel itself. A wire to the sending unit being grounded is the most likely cause on most systems.

While you use a DMM voltmeter function to evaluate voltage drop, the meter leads need to be connected in what way? A. To non-conductive material B. On the positive side of the circuit C. In series with the circuit D. Across the circuit or component

Correct answer D - You want to connect your meter leads across the circuit or component. Voltage always gets checked across the circuit or in parallel. The other answers aren't the appropriate way to connect meter leads in this situation.

1. The particles that orbit around the center of an atom are A) Electrons. B)Molecules. C)Nucleus. D)Protons

Correct! Electrons orbit around the nucleus of an atom