Automotive Electrical & Electronic Systems Classroom Manual

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the length of time a vehicle can be driven after the charging system has failed. The reserve capacity of a battery can be used to judge how much electrical drain in milliamperes could be acceptable using the reserve capacity in minutes divided by 4. For example, a battery with an RC rating of 120 minutes should have a maximum battery drain of 30 mA (120 4 30). Historical Ampere-Hour Rating The oldest battery rating method, no longer used to rate batteries, was the ampere-hour rating. This rating method was the industry standard for decades. It was replaced, however, years ago by the cranking performance and reserve capacity ratings, which provide better indications of a battery’s performance. The ampere-hour method was also called the 20-hour discharge rating method. This rating represented the steady current flow that a battery delivered at a temperature of 80°F (27°C) without cell voltage falling below 1.75 volts (a total of 10.5 volts for a 12-volt battery). For example, a battery that continuously delivered 3 amperes for 20 hours was rated as a 60 ampere-hour battery (3 amperes × 20 hours = 60 ampere-hours).

Historical Watt-Hour Rating Many years ago, batteries were rated in watt hours. A watt hour is the drain of a battery equal to one watt, which is one volt times one amp for a period of one hour or any combination of wattage and time. The watt hour rating of the battery was measured at 0°F ( 18°C).

Chapter Seven

vehicle. There are several different types of holddowns including: • Bracket over the top of the battery • Bottom bracket that wedges into a notch at

the base of the battery When selecting a battery, check the weight of the battery in the size that fits the vehicle. A heavier battery has more lead and is likely to out perform a lighter battery of the same size and type of construction.

Group Number Manufacturers provide a designated amount of space, usually in the engine compartment, to accommodate the battery. Since battery companies build batteries of various current-capacity ratings in a variety of sizes and shapes, it is useful to have a guide when replacing a battery, because it must fit into the space provided. The BCI size group number identifies a battery in terms of its length, width, height, terminal design, and other physical features.

BATTERY INSTALLATIONS Most automobiles use one 6-cell, 12-volt battery installed in the engine compartment. Certain factors influence battery location as follows: • The distance between the battery and the alter-

Battery Size Selection Battery size and weight are major factors for the design engineer. A typical battery can weigh about 50 pounds and takes space in the vehicle. Powertrain and electronic design engineers want the vehicle to have enough capacity for automatic headlights, which remain on for several minutes after the engine is turned off, as well as to provide the electrical power to start the engine under all extremely low temperature conditions. Due to vehicle packaging considerations, the battery can be located under the hood, behind the front bumper, under the rear seat, or in the trunk area. The battery selected must of course be able to fit into the vehicle and use the same cable converter as the original, as well as be able to be held down in the

nator or starter motor determines the length of the cables used. Cable length is important because of electrical system resistance. The longer the cables, the greater the resistance. • The battery should be located away from hot engine components in a position where it can be cooled by airflow. • The battery should be in a location where it can be securely mounted as protection against internal damage from vibration. • The battery should be positioned where it can be easily serviced. The decrease in size of late-model vehicles has resulted in lighter, smaller batteries with greater capacity. The use of new plastics and improved grid and plate materials has contributed to the new battery designs.


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Summary

4min
page 363

Cruise Control Systems

3min
pages 357-358

Review Questions

3min
pages 364-366

Radios and Entertainment Systems

6min
pages 337-339

Theft Deterrent Systems

7min
pages 353-356

Heated Seats

6min
pages 343-345

Power Seats

2min
pages 341-342

Power Door Locks, Trunk Latches, and Seat- Back Releases

2min
page 346

Heating and Air-Conditioning Systems

12min
pages 328-334

Class 2 IPM-Controlled HVAC Systems

2min
pages 335-336

Review Questions

1min
page 326

Summary

1min
page 325

Windshield Wipers and Washers

10min
pages 319-324

Summary

1min
page 314

Review Questions

2min
pages 315-316

Head-Up Display (HUD

5min
pages 311-313

Electromagnetic Instrument Circuits

11min
pages 296-300

Review Questions

2min
pages 293-294

Malfunction Indicator Lamp (MIL

5min
pages 301-303

Summary

1min
page 292

Instrument Panel and Interior Lamp Circuits

4min
pages 289-291

Circuits

1min
page 288

Backup Lamp Circuits Side Marker and Clearance Lamp

1min
page 287

Circuits

2min
page 286

Stop Lamp and Turn Signal Circuits Hazard Warning Lamp (Emergency Flasher)

6min
pages 282-285

Taillamp, License Plate Lamp, and Parking Lamp Circuits

1min
page 281

Common Automotive Bulbs

1min
page 280

Headlamp Circuits

16min
pages 270-279

Summary

1min
page 267

Review Questions

1min
page 268

Spark Plug Construction

4min
pages 264-266

Distributor Cap and Rotor

3min
pages 259-261

Primary and Secondary Circuits

1min
page 248

Voltages

4min
pages 246-247

Basic Circuits and Current

1min
page 241

Silicon-Controlled Rectifiers (SCRs

1min
page 233

Review Questions

2min
pages 236-238

Summary

1min
page 235

Transistors

9min
pages 229-232

Rectifier Circuits

2min
page 228

Semiconductors

7min
pages 222-224

Photonic Semiconductors

2min
page 227

Review Questions

3min
pages 218-220

Starter Motor and Drive Types

8min
pages 210-214

DC Starter Motor Operation

5min
pages 206-208

Summary

2min
pages 216-217

Overrunning Clutch

1min
page 215

Specific Starting Systems

6min
pages 200-203

Summary

2min
pages 191-192

Differences

13min
pages 183-190

Review Questions

3min
pages 193-194

Charge/Voltage/Current Indicators

3min
pages 180-181

Solid-state Regulators

9min
pages 175-179

Electromagnetic Regulators

1min
page 174

Voltage Regulation

2min
page 173

Current Production in an AC Generator

9min
pages 168-172

Diode Rectification

3min
pages 162-163

AC Generator (Alternator) Components

7min
pages 164-167

Review Questions

4min
pages 157-158

Battery Installations

4min
pages 150-151

Battery Installation Components

2min
pages 152-153

Summary

2min
page 156

Battery Life and Performance Factors

5min
pages 154-155

State-of-Charge Indicators Wet-Charged and Dry-Charged

2min
page 147

Battery Electrolyte

2min
page 146

Electrochemical Action

8min
pages 142-145

Review Questions

3min
pages 138-140

Wire Color Coding

2min
pages 121-122

Multiplex Circuits

8min
pages 112-114

Ground Paths

2min
page 111

Connectors and Terminals

5min
pages 108-110

Wire Size

6min
pages 105-107

Wire Types and Materials

2min
page 104

Wiring and Harnesses

2min
pages 102-103

Review Questions

4min
pages 97-100

Parallel Circuit Voltage Drops Calculating Series Circuit Total

1min
page 87

Series and Parallel Circuit Faults

3min
pages 94-95

Series-Parallel Circuits

4min
pages 91-93

Review Questions

2min
page 82

Summary

3min
pages 80-81

Electromagnetism

9min
pages 67-71

Electromagnetic Induction

11min
pages 72-76

Magnetism

2min
page 66

Power

2min
page 56

Capacitance

8min
pages 57-60

Review Questions

2min
pages 62-64

Summary

1min
page 61

Complete Electrical Circuit

3min
pages 52-53

Summary

2min
page 43

Historical Figures in Electricity

2min
page 42

Fire Extinguishers

1min
page 31

Safety Tips for Technicians

2min
pages 25-26

Nuts

1min
page 15

Review Questions

2min
pages 44-46

Electrical Cord Safety

1min
pages 29-30

Safety in Lifting (Hoisting) a Vehicle

2min
pages 27-28
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