This unique handbook assumes no starting knowledge of car electrical and electronics systems. It begins with simple circuits and finishes with complex electronic systems that include engine management, transmission control and stability control systems. If you want to diagnose a simple alternator charging or headlight problem, this book is for you. But if you also want to fix complex electronic systems using On-Board Diagnostics, a multimeter or oscilloscope, this book also shows you how to do that. Is it best to use a series or parallel circuit when adding a horn? How do you use a multimeter to check a coolant temperature sensor against its specs? How can you add an electronic timer that will keep your headlights on as you walk to your door? When should you buy an oscilloscope – and how complex an instrument do you really need? The author has been writing about car electronic systems for over 25 years. He is also an experienced and proficient car modifier who has performed numerous electronic modifications and upgrades to his own cars, including world-first modifications. If you want a practical, hands-on book that demystifies and explains car electrical and electronic systems, this is the book for you.