Chapter 32&33
What is the base voltage reading of a fully charged battery
12.6 volts
The voltage regulator can maintain a present charging voltage of ___ volts
13-15
Voltage regulator switching is very fast, about ____ cycles per second to help prevent radior noise
400
Technician A says you should disconnect the battery before connecting it to a battery charger. Technician B says electronic components have internal protection from the high voltages of the battery charger. Who is right?
A only
An alternator uses all of the following for power, except: A) V-Belt B) Chain C) Cogged V-Belt D) Ribbed Belt
Chain
All of the following are main components in a typical alternator, except: A) Rotor assembly B) Brush assembly C) Charge indicator D) Housing
Charge indicator
An insulated-circuit resistance test indicates a portion of the charging system circuit has a voltage drop of 1.9 volts. What does this indicate?
Circuit resistance is high and poor connection exists in that section of the charging circuit
A _____ may be used to supply current to the rotor field windings
Diode trio
When removing an alternator, what should be done first?
Disconnect the battery to prevent a major electrical short and wiring harness
The ____ is the percentage of time that current is fed to the alternators field windings
Duty Cycle
all of the following test equipment can be used to perform a charging system test, Except: A) dwell-tach B) load tester C) scope tool D) common VOM
Dwell-tach
The ____ is sometimes used to supplement or replace the conventional voltage regulator to more precisely control the charging circuit
Engine control module
A ____ diode acts as a conductor
Forward-biased
Describe the operation of an alternator warning light
If problems develop in the charging system, the field current, trying to increase alternator output, will increase enough to light the indicator bulb. If the charging system is in good operating condition, current flow through the field will be too low to light the bulb
What is the most common type of voltage regulator used today?
Integral
What will happen when a hybrid vehicle has been driven its maximum range on electric power alone?
It will start the internal combustion to practically recharge the battery, propel the car, and operate conventional 12-volt circuits
All of the following are charge indicators, except: A) MIL Light B) Warning light C) Voltmeter indicator D) Ammeter indicator
MIL light
Describe alternator bearings and state their purpose
Needle or ball types, they are used to produce a low-friction surface for a rotor shaft
technician A says the alternator rear bearings are frequently held in place with a small plate and screws. Technician B says alternator front bearings are usually press-fit. Who is right?
Neither A nor B
Should you operate the alternator with the output wire disconnected? Explain your answer
No, alternator voltage can increase above normal levels. Alternator or charging circuit damage could result
A ____ diode acts as an insulator
Reverse- biased
What should you suspect if alternator output current is low?
Suspect a bad alternator/ regulator assembly
When should a charging system test be performed?
When symptoms point to low alternator voltage and current
How do you check for abnormal noise from an alternator
While the engine is running. If necessary use a stethoscope to listen for dry, noisy alternator bearings
Define Alternator Rectifier
also called a diode assembly commonly uses six diodes to convert starter current to direct current
The simple alternator produces a ____ current output
alternating current (AC)
What two factors determine whether the regulator increases or decreases charging output
alternator speed and load
What is an alternator
an AC generator that uses mechanical power to produce electricity
What is a diode
an electronic device that allows current flow in only one direction
Before testing the charging system, it is common practice to check the condition of the _____
battery
load test
involves using a load tester to check the current and voltage output of the charging system
Scope test
involves using a scope to analyze voltage waveforms produced by charging system
voltmeter test
is used to quickly check the general output of a charging system
Name three functions of the charging system
it recharges the battery after engine cranking or after the use of electrical accessories with engine shut off. It supplies all the vehicles 12-Volt electricity when the engine is running. It provides a 13-15 volt output, which is slightly higher than a battery fully-charged at 12.6 volts
What purposes does the drive belt serve?
links the engine crankshaft pulley with the alternator pulley to drive the alternator
A _____ provides the most accurate method of checking a charging system
load tester
Describe three or more things you would check during an inspection of a charging system
loose battery cables, a discharged battery, corroded terminals, or low water level, or damaged battery case, belt tension, condition of alternator drive, wiring problems, abnormal noises
List three wiring problems a circuit resistance test can locate
loose connections, corroded terminals, and partially burned wires
All of the following steps should be performed when installing an alternator except: A) check the condition of the alternator belt and replace if needed B) install and torque the mounting bolts C) Measure the resistance of the ignition coil windings D) reconnect the wiring harness
measure the resistance of the ignition coil windings
Circuit resistance tests
measures resistance in insulated and ground circuits of the system
Name a three major parts of a hybrid charging system
motor generator hybrid instrumentation HV power control module
describe an alternator pulley
provides a means of spinning the rotor through the use of a belt
how does the battery serve the charging system
provides current to initially energize and smooth DC current output from the alternator
The alternator current must be ___ into direct current before entering the vehicle's electrical system
rectified
the (rotor, stator) is located in the center of the alternator housing
rotor
on most vehicles with self-diagnostic systems, you can connect a _____ to the vehicle to aid in troubleshooting
scan tool
A charging system _____ test involves analyzing the alternator voltage waveform for signs of abnormal ripple
scope
A problem described as a no-charge condition may be caused by a _____.
shorted starting motor And/or battery drain
The ____ is a set of windings that surrounds the rotor
stator
How is a ground-circuit resistance test different from an insulated-circuit resistance test?
the voltmeter is placed across the negative battery terminal and alternating housing
Scan tool test
this test involves using a load tester to check the current and voltage output of the charging system
Describe alternator slip rings and state their purpose
to provide DC current to the rotors field windings
What is the job of the alternator fan?
to provide forced-air cooling for the alternator
True or False? The alternator speed determines whether the regulator increases or decreases charging output
true
Describe the makeup of the alternator rotor
two claw-shaped pole pieces surround the field windings to increase the magnetic flux or the magnetic field strength
What is the purpose of a circuit resistance test
used to locate wiring problems in a charging system, such as loose connections, corroded terminals, partially burned wires, and similar troubles
Explain the construction and elements of a voltage regulator
uses an electric circuit to control alternator output by changing the amount of current flowing through the rotors field windings
What is overcharging
when excess current is forced through the battery
List the steps typically involved with an alternator rebuild
-disassemble the alternator -inspecting and testing the rotor -inspecting and testing the stater -testing the diodes -replacing the rotor, stator, and diodes if they are defective -replacing the bearings -replacing the brushes - reassembly and testing the alternator
List five precautions to follow when working on a charging system
1. Disconnect the battery before removing any charging system component 2. Disconnect the battery before connecting it to a battery charger 3. Never reverse polarity 4. Do not operate the alternator with the output wire disconnected 5. Never short or ground any charging system terminal instructed to do so by a shop manual
Technician A says a charging system problem will have a little effect on other vehicle systems. Technician B says that sometimes, another system fault will appear to be caused by charging system problems. Who is right?
B only
Technician A says a no-load voltage reading of 0.5-2 volts higher than the base voltage is normal. Technician B says is no-lead voltage is more than 2-3 volts higher than base voltage, the alternator is overcharging the battery. Who is right?
B only
Technician A says extended overcharging is okay. Technician B says overcharging can result in battery overheating. Who is right?
B only
Two technicians are discussing scope meter usage. Technician A says you should connect both scope leads to the alternator output terminal. Technician B says you should connect one lead to the alternator output terminal and the other to the ground. WHo is right?
B only
name two of the most common problems with HV charging systems
Bad HV PCM and bad motor generator
Technician A says an electronic voltage regulator is a sealed unit and cannot be repaired. Technician B says the circuits of an electronic voltage regulator are surrounded by a rubber-like gel. Who is right?
Both A and B
Technician A says that if a hybrid vehicle battery fails to take or hold a proper electrical charge, a trouble code will be set. Technician B says that the best way to become properly trained to diagnose and repair a hybrid charging system is to attend factory training courses or read manufacturer instructions on the specific make and model. Who is right?
Both A and B
Technician A says the voltage regulator keeps alternator output at a present charging voltage. Technician B says the charging voltage is 13-15 volts. Who is right?
Both A and B
Technician A says, depending on vehicle design, the alternator can come out from the the top. Technician B says, dependending on vehicle design, the alternator can come out from the bottom. WHo is right?
Both A and B
Small ____ hold the brushes in contact with the slip rings
Brush springs
Technician A says an alternator uses several diodes. Technician B says using several diodes results in smooth current flow. Who is right?
C
Where are rectifier diodes placed
in a diode frame or heat sink (Metal mount for removing excess heat from electronic parts)
All of the following will occur if battery polarity is reversed, except: A) Damage to the diodes in the alternator B) The battery will recharge faster C) Damage to the voltage regulator circuits D) Damage to electronic components in computer systems
The battery will recharge faster
The control module can monitor charging system output and react to changing operating conditions. Explain what this means?
The module can shut off the alternator at wide open throttle for better vehicle acceleration. Saving several horsepower
Explain how the electronic voltage regulator words?
The voltage regulator allows more current in to the rotor windings. This strengthens the magnetic field around the rotor.. More current is then induced in the starter windings, increasing alternator output. To reduce alternator output, the regulator places more resistance between the battery and field windings. magnetic field strength drops and less current is induced to the stator windings
A battery ____ is used to measure battery temperature so the charging system can alter charging output as needed
Thermistor
True or False? A heated windshield produces enough voltage to cause electrocution
True
Why do some modern electronic voltage regulators progressively switch on charging voltage
if the full load of the alternator were to come on instantly, it could lug the idling engine down
The ____ is an ammeter, voltmeter, or warning light that informs the driver of charging system condition
charge indicator
List the seven steps involved in performing a voltmeter test of the charging system
charge the battery, if it was drained before testing. Set the voltmeter to read low voltage. Connect the voltmeter test leads across the battery terminals. Measure and record base voltage. Start the engine and record the no-load voltage. Calculate charge voltage using the formula: Load - base = charge in DC
Describe the construction of an alternator stator
consists if three sets of windings. Each set is wrapped around a laminated iron core. The iron core is used to be concentrate and strengthen the field around the stator windings
what does the voltage regulator do?
controls the voltage and current output of an alternator
The voltmeter simply shows the voltage, which is an indicator of ____ output and charging system condition
current
An automobile electrical system is designed to use ____ current
direct
With the battery ____, fit the alternator onto the engine
disconnected
What is an alternator failsafe circuit
disconnects the alternator output if voltage levels become to high
what is the best way to determine the strength of a hybrids charging system
drive up a small hill
True or False? HV PCMs generate equal amounts of voltage for the various electrical systems
false
The charging system ___ is the wiring that electrically connects the components together
harness