Charging systems
An acceptable charging circuit voltage on a 12 volt system is ________. 13.5 to 15 volts 12.6 to 15.6 volts 12 to 14 volts 14.9 to 16.1 volts
A) 13.5 to 15 volts
One horsepower is equal to ________ watts. 746 500 1050 None of these
A) 746
What test is being performed in this illustration (engine running)? AC ripple voltage test Alternator voltage output test Charging system current test Diode test
A) Ac ripple voltage test
What test is being performed in this illustration (engine running? Alternator output voltage drop test Charging current test Alternator ground circuit test Battery voltage test
A) Alternator output voltage drop test
To check the charging voltage, connect a digital multimeter (DMM) to the positive (+) and negative (-) terminals of the battery and select ________. DC volts AC volts DC amps AC amps
A) Dc volts
Alternators induce voltage by rotating which of these? Magnetic field inside a fixed conductor Conductor around a fixed stator Stator inside a magnetic field Diodes inside a magnetic field
A) Magnetic field inside a fixed conductor
Which of these facts is correct about a delta-wound stator? No neutral junction No ground connection The windings always form a series circuit The circuit diagram looks like a parallelogram
A) No neutral junction
Identify this alternator component. Rectifier bridge Diode trio Stator linkage Alternator end housing
A) Rectifier bridge
Which of these is TRUE about an alternator with an overrunning pulley? Replacement pulley must be the overrunning type It can use a conventional replacement pulley Both A and B Neither A nor B
A) Replacement pulley must be the overrunning type
Current for the rotor flows through the brushes to the ________. Slip rings Stator Rotor Regulator
A) Slip rings
Technician A says that a magnetic field is created in the alternator rotor. Technician B says that alternator output is increased if the speed of the alternator is decreased. Who is right? Technician A only Technician B only Both technicians A and B Neither technician A nor B
A) Technician A only
Technician A says that a voltage drop test of the charging circuit should only be performed when current is flowing through the circuit. Technician B says to connect the leads of a voltmeter to the positive and negative terminals of the battery to measure the voltage drop of the charging system. Who is right? Technician A only Technician B only Both technicians A and B Neither technician A nor B
A) Technician A only
Technician A says that charging system testing requires that the battery be at least 75% charged. Technician B says that a digital multimeter can not be used to test charging system voltage. Who is right? Technician A only Technician B only Both technicians A and B Neither technician A nor B
A) Technician A only
Technician A says that an alternator overrunning pulley is used to reduce vibration and noise, Technician B says that an overrunning alternator pulley or dampener uses a one-way clutch. Who is right? Technician A only Technician B only Both technicians A and B Neither technician A nor B
C) Both technicians A and B
Technician A says that by full fielding the alternator, you are bypassing the voltage regulator. Technician B says that full fielding can possibly damage electronic circuits, so it is no longer a recommended test. Who is right? Technician A only Technician B only Both technicians A and B Neither technician A nor B
C) Both technicians A and B
Technician A says that current is created in the stator windings of an alternator. Technician B says that the voltage regulator controls the current flow through the rotor. Who is right? Technician A only Technician B only Both technicians A and B Neither technician A nor B
C) Both technicians A and B
Technician A says that the computer can be used to control the output of the alternator by controlling the field current. Technician B says that voltage regulators control the alternator output by controlling the field current through the rotor. Which technician is correct? Technician A only Technician B only Both technicians A and B Neither technician A nor B
C) Both technicians A and B
Technician A says that two diodes are required for each stator winding lead. Technician B says that diodes change alternating current into direct current. Technician A only Technician B only Both technicians A and B Neither technician A nor B
C) Both technicians A and B
The output diodes in an alternator are mounted to which of these components? Stator Rotor Housing Slip rings
C) Housing
A magnetic field is created in the ________ in an alternator. Stator Diodes Rotor Frame
C) Rotor
Why should the lights be turned on when checking for ripple voltage or AC current from the alternator? To warm the battery To check that the battery is fully charged To create an electrical load for the alternator To test the battery before conducting other tests
C) To create an electrical load for the alternator
Which of these components is the stator? A B C D
D)
An alternator diode is being tested using a DMM (digital multimeter) set to the diode check position. A good diode will read ________ if the leads are connected one way across the diode and ________ if the leads are reversed. 300 ohms/300 ohms 0.475 ohms/0.475 ohms OL/OL 0.551 ohms/OL
D) 0.551 ohms/OL
The maximum allowable alternating current (AC) in amperes that is being sent to the battery from the alternator is ________. 0.04 A 1 to 3 A 3 to 4 A 10% of the rated output of the AC Generator
D) 10% of the rated output of the AC Generator
The voltage regulator controls the current through the ________. Alternator brushes Rotor Alternator field All of these
D) All of these
An alternator could test as producing lower-than-normal output, yet be okay, if the ________. Battery is weak or defective Engine speed is not high enough during testing Drive belt is loose or slipping Any of the above
D) Any of the above
Alternator brushes are constructed from ________. Copper Aluminum Silver-copper alloy Carbon
D) Carbon
All of these alternator components should be electrically tested, EXCEPT ________. Stator Rotor Diodes End Frame
D) End Frame
Technician A says when testing for maximum alternator output, the battery must be loaded to force the alternator to produce its maximum output. Technician B says after disassembly, all alternator internal components should be tested using an ammeter. Who is right? Technician A only Technician B only Both technicians A and B Neither technician A nor B
A) Technician A only
Some alternators are cooled by engine coolant. 1) True 2) False
A) True
On a vehicle using an electrical power management system (EPM), how is the current to the battery measured? With a Hall effect sensor With an in-line ammeter By using a custom voltmeter By use of a duty-cycle sensor
A) With a Hall effect sensor
How much current flows through the alternator brushes? All of the alternator output flows through the brushes 2-5 25 to 35 A, depending on the vehicle 10 to 15 A
B) 2-5
To check for ripple voltage from the alternator, connect a digital multimeter (DMM) and select ________. DC volts AC volts DC amps AC amps
B) AC Volts
When testing an alternator rotor, if an ohmmeter shows zero ohms with one meter lead attached to the slip rings and the other meter lead touching the rotor shaft, the rotor is ________. OK (normal) Defective (shorted-to-ground) Defective (shorted-to-voltage) OK (rotor windings are open)
B) Defective (shorted-to-ground)
A duty cycle of 90% means the circuit is off most of the time. 1) True 2) False
B) False
The GM electrical power management system has 3 modes of operation. :1) True 2) False
B) False
Electronic voltage regulators use a temperature-sensitive resistor in the regulator circuit. This resistor, called a thermistor, provides lower resistance as the temperature ________. Decreases Increases Stays the same Doubles
B) Increases
Operating an alternator in a vehicle with a defective battery can harm the ________. Diodes (rectifier bridge) Stator Voltage regulator Brushes
B) Stator
The alternator output current is produced in the ________. Rotor Stator Regulator Diodes
B) Stator
A vehicle battery is consistently low on voltage. Technician A says to disconnect the battery with the engine running to test for proper alternator output. Technician B says that a loose alternator belt may cause this problem. Who is right? Technician A only Technician B only Both technicians A and B Neither technician A nor B
B) Technician B only
Technician A says that a loose drive belt could cause overcharging. Technician B says that undersized wiring between the alternator and the battery could cause undercharging. Who is right? Technician A only Technician B only Both technicians A and B Neither technician A nor B
B) Technician B only
Technician A says that a wye-wound stator produces more maximum output than the same alternator equipped with a delta-wound stator. Technician B says that an alternator equipped with a delta-wound stator produces more maximum output than a wye-wound stator. Who is right? Technician A only Technician B only Both technicians A and B Neither technician A nor B
B) Technician B only
Technician A says that the diodes regulate the alternator output voltage. Technician B says that the field current can be computer controlled. Who is right? Technician A only Technician B only Both technicians A and B Neither technician A nor B
B) Technician B only
An alternator stator with three windings usually has how many diodes? 2 4 6 8
C) 6
An alternator has no output. Technician A says that the alternator field circuit may have an open circuit. Technician B says that the fusible link may be open in the alternator to battery wire. Who is right? Technician A only Technician B only Both technicians A and B Neither technician A nor B
C) Both technicians A and B