Auto Upkeep Basic Car Care, Maintenance, and Repair (2 nd Edition) Electrical System

Auto UpkeepBasic Car Care, Maintenance, and Repair (2nd Edition)

Electrical System

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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.

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Electrical Terms

• 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

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Roadside Emergencies

• Jump-starting

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.