Haynes Automotive Heating and Air Conditioning Systems Manual

Book Preface

There was a time when every good mechanic understood the basic svstems of the automobile pretty well. But that time ha~-~asseTdh.e days of the renaissance repairman are over. As systems have become more complicated, the investment in training and tools necessary to service the entire range of automotive technology found on a typical modern vehicle has widened to the point that no one actually “fixes cars” anymore. Instead, most modern mechanics specialize. Today, we have engine builders, front end specialists, tune-up specialists, transmission specialists, etc. Unfortunately, this approach has created an aura of “black magic” around the more esoteric of these topics.

Automotive air conditioning is certainly one subject that is poorly understood by nearly all do-it-yourselfers and a lot of professionals as well. The reasons for this situation come down to motivation, money and knowledge. Unlike performance-related topics such as degreeirlg a cam, rejetting a carburetor, etc., air conditioning theory, service and troubleshooting is, frankly, pretty dry stuff. A well maintained air conditioning system won’t make a vehicle faster. But it will make it more comfortable. Unfortunately, performance – not comfort – is what gets young mechanics going. Consequently, they don’t usually grow up saying “I want to be an air conditioning technician.”

Then there are the special tools. Even if you are the kind of person who is attracted to air conditioning work, the tools needed to diagnose, repair and maintain a typical system are highly specialized and expensive. They’re so specialized, in fact, that they can’t be used for much else. Only a professional who chooses the field as a career can justify the kind of investment it takes to become an air conditioning specialist.

Another reason air conditioning seems so mysterious is that little useful knowledge of the basics is readily available. Lots of books explain how to service specific systems, but few bother with the underlying principles of operation. This is unfortunate, because a good grasp of basic theory can enable a mechanic to understand any air conditioning system.