Transcript Powerpoint - Mr. Bunce Box Elder Automotive

Auto Upkeep
Basic Car Care, Maintenance, and Repair (2nd Edition)
Electrical System
b
Fuel for Thought
• What is the purpose of an automotive
battery?
• What is the difference between voltage,
current, and resistance?
• Why is it important to replace a blown fuse
with the correct amperage rating?
Objectives
• Upon completion of this power point and
activities, you will be able to:
– Define electricity in terms of voltage, current, and
resistance.
– Identify and describe the components in the starting
and charging system.
– Explain battery performance ratings.
– Identify the importance of fuses in the electrical
system.
– Test the starter and alternator.
– Clean and test a battery safely.
Electrical Terms
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Electricity is the flow of electrons.
Conductors allow electron flow.
Insulators restricts the flow of electrons.
Voltage is the pressure pushing electrons (Electromotive force).
Current is the quantity of electrons (Intensity).
Resistance is the measure of electrical resistance.
Battery
• 12-Volt Systems
– Most automotive batteries are 12-volt DC.
– Each cell produces 2 to 2.1 volts.
Battery Ratings
• CCA – Cold Cranking Amps tested at
0ºF (-18ºC)
• CA – Cranking Amps tested at 32ºF (0ºC)
Battery Maintenance
• Some batteries are permanently sealed.
• Others you can check the specific gravity in
each cell.
Higher Voltage Systems
Starting System
Starter
• Converts electrical
energy into
mechanical energy to
crank the engine.
Charging System
Drive Belt
• The routing
diagram can
help you install
a new belt.
Serpentine and V
• Serpentine
• V
Alternator
• Converts mechanical
energy to electrical
energy to recharge
the battery.
Voltage drop
• You always want to perform a voltage drop
test when checking out a charging problem.
Also can be called a circuit resistance test.
• You need to check the ground side and the
insulated side vehicle must be running and
a load must be applied. You can add a
load by just turning on the lights, heater
and other accessories.
Voltage drop Insulated
• Hook up Positive
lead to the output of
the alternator
• Hook up Negative
lead to the Positive
terminal of the
battery
Voltage drop Insulated
• The reading should be less then .5 Volts This
one is at .154 volts.
Meter should be
in the DC volt
scale
Voltage drop ground side
• Hook up Positive
lead to the
Negative side of
the battery.
• Hook up the
negative lead to
the frame of the
alternator.
Voltage drop ground side
• The reading should be less then .2 Volts
This one is at .036 volts.
Fuses
• Fuse Junction Block
• Fuse Types
Fuses – Blown Fuse
• Never replace with a higher amp rating.
Flashers, Relays,
and Circuit Breakers
• Flashers are used to
operate turn signals and
hazard lights.
• Relays allow a small
current to control a circuit
with a high current.
• Circuit breakers reset
automatically.
Lights
• Automotive miniature
bulbs
• Automotive headlights
Aiming head Lights
Roadside Emergencies
• Jump-starting
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Summary
• Clean and maintain your vehicle’s battery.
• Starting system converts chemical energy to
electrical energy to mechanical energy.
• Charging system converts mechanical energy to
electrical energy to chemical energy.
• Replace lights when they burn out for safety.
• Check the specific gravity in each cell.
• The PCM stores trouble codes to help you
diagnose problems.