Automotive Electrical and Electronic Systems

Author: Holumbick (USA)
Translator: Xu Ming et al.
Editor-in-Chief: Wu Boqing
Publisher:
Publishing Date: 2000-07-01
Features: Preface to Editing and Publishing
Automobiles are increasingly penetrating into all aspects of social life and daily life, and automobile repair has become a prominent and rapidly developing industry. In today's era, the integration of mechanical technology and electronic technology has brought about profound changes in automotive technology. The widespread application of new technologies such as electronic-controlled automatic transmission, electronic-controlled fuel injection, and anti-lock braking systems has made the internal structure of modern automobiles increasingly sophisticated and complex. This has placed higher demands on automobile maintenance personnel, who must not only master general repair techniques but also understand the basic structure, working principles, and advanced fault diagnosis technologies of modern automobiles, especially passenger cars.
The newly published "Contemporary Automotive Technician Series" by Delmar Publishers in the United States is a set of excellent self-study and training materials for automobile maintenance personnel. It comprehensively introduces the structures of various passenger cars and light commercial vehicles, including mechanical and electrical/electronic systems, and provides detailed explanations of the inspection and repair procedures and restoration techniques for each part of the vehicle, accompanied by illustrations and clear stereoscopic diagrams. Among the numerous automobile repair books available in China, this series stands out in both content and form, so we have decided to introduce it to domestic readers.
The original series consists of ten books, and we have selected six of them: "Automotive Manual Transmission and Drivetrain," "Automotive Automatic Transmission and Drivetrain," "Automotive Electrical and Electronic Systems," "Automotive Braking Systems," "Automotive Heating and Air Conditioning Systems," and "Automotive Computer Control Systems." To adapt to the reading habits of Chinese readers and combine with the specific conditions of our country, appropriate modifications were made during the translation and publication process, mainly including:
(1) The original books were published as two separate volumes: a classroom manual and a workshop manual. For convenience of use, they have been combined into one book, divided into an upper part—theoretical section and a lower part—practical section.
(2) The original books included side annotations for professional term definitions, tool lists, and reference information. Only the most practical annotations were incorporated into the corresponding main text.
(3) The ASE (Automotive Service Excellence) maintenance skill diagnostic tables in the original books listed reference page numbers for the classroom and workshop manuals, as well as reference page numbers in side annotations. In this book, these have been replaced with corresponding chapter numbers in the upper and lower parts.
(4) The glossary at the end of the original books was not adopted due to its limited practical value.
The last point to mention is the issue of translation naming. Due to the rapid development of automotive technology, a large number of new technical terms and components have emerged, and the domestic automotive industry has yet to establish unified standards for naming them. This has posed significant challenges for translation. For such terms, expert translators have attempted to provide appropriate translations based on industry conventions and their own understanding. There may be instances where the translations are not entirely accurate or even inappropriate, and we welcome readers' feedback and corrections.
This book discusses the fundamental theories and maintenance principles of automotive electrical and electronic systems, introducing the working principles and wiring of batteries and charging systems, lighting circuits and advanced lighting systems, analog and electronic instruments, indicator lights and warning devices, DC motors and starting systems, body computers, chassis electronic control systems, and electrical accessories. It also covers common faults, their causes, diagnostic methods, repair techniques, and safety operation guidelines.
The book is divided into two parts, totaling 26 chapters. The upper part is the theoretical section, and the lower part is the practical section. Each chapter concludes with a summary, case studies in maintenance, ASE fault diagnosis tables, and ASE-style review questions. The book is accompanied by numerous illustrations, and the lower part includes numerous series photos to illustrate maintenance processes.
This book is suitable for automotive maintenance technicians and engineers, as well as for use as a textbook for professional theory and maintenance skill training.
Excerpt:
In an automotive repair workshop, wearing jewelry is prohibited, especially when working on electrical systems. Rings, watches, bracelets, necklaces, earrings, and other jewelry can cause accidents. Precious metals like gold and silver are excellent conductors, and your body is also a conductor. When current flows through a conductor, it generates heat. If jewelry causes a short circuit in the circuit, the heat generated can result in severe burns. Additionally, jewelry can get caught in moving parts or equipment, breaking your fingers or hands. In particular, necklaces can lead to serious injuries or even death if they get entangled in operating components or equipment.
Since the human body is a conductor, wearing shoes can provide electrical insulation. Wear sturdy shoes or boots with oil-resistant soles to prevent heavy objects from crushing your feet. In an automotive repair workshop, it is not advisable to wear tennis shoes or athletic shoes.
1.2.2 Eye Protection
The importance of wearing appropriate eye protection cannot be overstated, yet many eyes are injured every workday, some even losing their sight. However, most of these injuries are preventable. The safest and most reliable way to protect your eyes is to wear appropriate eye protection as soon as you enter the workshop. At the very least, you should wear eye protection when sanding, using power tools, hammers, chisels, or working under the vehicle. You must wear eye protection when performing tasks that may cause sparks, dust, or metal fragments to enter your eyes, as well as when working around chemicals. Do not assume that your eyes are safe just because you are not working—many injuries are caused by flying debris from coworkers' activities.
The key to protecting your eyes is wearing appropriate eye protection. Regular glasses provide little protection. The impact resistance standards for regular glasses are far lower than those required in the workplace. A flying debris may be blocked by the lens, but the frame could cause the lens to break irregularly, resulting in injury. Moreover, regular glasses do not protect against side-sprayed objects. There are various types of popular eye protection devices available (Figure 1-2). Safety glasses can protect your eyes. These glasses are lightweight and comfortable, with lenses made of tempered glass or safety plastic. The lenses and frames are designed to withstand impact, and they include side shields to prevent objects from entering from the sides. They can also be fitted with different prescriptions. Safety goggles fit snugly around the eye sockets, conforming to the contours of the eyes and forehead, providing protection against foreign objects and splashing liquids. The force impacting the lens is distributed over the total contact area between the goggles and the face and forehead. Additionally, safety goggles can be worn over regular glasses. A face shield is a transparent plastic cover that protects the entire face and is used in situations where sparks, flying debris, or splashing liquids may cause injury to the face and eyes. However, since the plastic components of face shields are less strong and impact-resistant than safety glasses or goggles, they should be used in conjunction with other eye protection devices in situations where strong impact objects pose a risk to the face shield.
Note: Before removing eye protection, it is best to close your eyes to prevent metal shavings, dust, or other foreign objects from falling into your eyes when you remove the device.
1.2.3 Working Around Rotating Belts and Pulleys
When working around rotating components such as the generator, power steering pump, compressor, water pump, and air conditioning compressor, technicians must plan ahead and remain vigilant about where to place their hands and fingers at all times. Rags, tools, or testing equipment should not be placed near moving parts. Avoid wearing loose clothing or jewelry. Extra caution is required when working near electric cooling fans. Even with the ignition switch turned off, these fans may still rotate because they are controlled by temperature sensors mounted on the engine cylinder head or radiator. As soon as the coolant temperature reaches a certain level, they begin to rotate. Therefore, it is advisable to disconnect the fan motor connector or the negative battery cable when working near them.
Warning: If the fan connector is not connected before the vehicle is put into use, it may cause engine damage.
Other rotating equipment and components related to safe operation include tire changers, dynamic balancers, drill presses, bench grinders, and driveshafts.
1.2.4 Lifting Heavy Objects
Back injuries are among the most severe types of industrial accidents, but many of them can be prevented. Most such injuries are caused by lifting heavy objects. Adhering to the following rules for lifting heavy objects can help prevent injuries:
(1) Do not lift heavy objects alone; ask for help.
(2) Lift only what you can handle. If an object is too heavy, do not force it; use appropriate lifting tools.
(3) Do not attempt to lift objects you are not sure you can hold firmly. Think about the object's center of gravity and the points where you should grip it.
(4) Do not lift heavy objects with your back; use your leg muscles, which are stronger.
(5) Keep your body close to the object and maintain a straight back and straight elbows (Figure 1-3).