3
Auto Heating & Air Conditioning has been written
to introduce you to the basic principles of vehicle climate
control, including cooling, heating, defrosting, and air
distribution. It is also intended to give you a thorough under-
standing of how to diagnose and repair all components used
in automotive heating, cooling, and ventilating systems.
Not too long ago, cooling an automobile or truck inte-
rior was a luxury only the wealthiest buyers could afford.
Today, air conditioning is standard equipment on almost
all new vehicles. Heating and ventilation has been a part
of the automobile for many years. The widespread use of
automotive air conditioning creates a tremendous oppor-
tunity for the technician. This book will help you to take
advantage of the opportunity.
Some heating and cooling concepts were discovered
and put to use before the automobile was developed. Other
concepts, such as electronic controls, have only recently
been developed. On many vehicles, the control system
for the air conditioning and heating system is part of the
on-board computer. Many service procedures can only
be performed with special tools and test equipment. You
must know how to use these special testers and tools. For
this reason, the technician must be able to take a logical
approach to service, backed up by a thorough knowledge
of system operation. Diagnosing air conditioning and heat-
ing systems also requires special test equipment.
Technicians must know how to fi nd and comprehend
diagnostic procedures, test specifi cations, and other diag-
nosis and repair information. In many cases, information is
provided on compact discs or on the Internet. The techni-
cian must therefore know how to operate a computer. The
technician must be familiar with Environmental Protection
Agency (EPA) laws and related state laws governing refrig-
erant use and release of refrigerant into the atmosphere.
Auto Heating & Air Conditioning has been carefully
designed so all system parts and operating principles will be
fully identifi ed and explained before you begin work on actual
systems installed in vehicles. Early chapters cover basic prin-
ciples and parts. Later chapters cover service and repair opera-
tions, building on the material covered in the earlier chapters.
As you work through this text, you will be introduced to basic
principles and perform simple tasks involving these principles.
Only then will you move on to more complex tasks. At no
time will you be asked to service a system or part before you
understand its construction and function.
Throughout this text, you will be directed to sources
of specifi c service information, such as specifi cations and
disassembly and reassembly procedures. Additionally you
will be informed of safety related issues, and to proper and
safe methods of performing diagnosis and service. EPA and
state laws governing refrigerant handling will be covered.
You will also learn about basic electrical principles and
computer controls. Appendix A covers the principles and
service of heated rear windows and mirrors.
Auto Heating & Air Conditioning can also be used to
prepare for ASE tests. It is very diffi cult to get a job as an
automotive technician without ASE certifi cation. This book
covers all the HVAC service and repair principles you will
need to know to pass the ASE Heating and Air Conditioning
certifi cation test. Many of the questions in the book are
presented in the same format as those used in the actual
ASE Heating and Air Conditioning certifi cation test. ASE-
type questions are included at the end of each chapter. In
addition, all of Chapter 24 is devoted to information about
applying for, taking, and passing the ASE tests.
A companion book to Auto Heating & Air Conditioning
is the Workbook for Auto Heating & Air Conditioning. The
workbook contains additional test questions (many in ASE
format), and jobs that test your hands-on ability. The chap-
ters in the workbook correspond to the chapters in Auto
Heating & Air Conditioning.
Chris Johanson
Introduction