The Hands-On Vehicle Testing Reference
A proven, shop-tested guide to diagnosing electrical and electronic systems without guesswork.
A Practical Guide You’ll Actually Use
This book was created for technicians and DIY mechanics who want a simple, reliable way to diagnose electrical and electronic problems. Instead of theory-heavy explanations or confusing flowcharts, this guide shows you the exact shop-tested procedures that Joe has taught to thousands of technicians over 29 years. These techniques eliminate guesswork, reduce part-swapping, and build confidence with every test you perform.
What You’ll Learn
By the end of this book, you’ll know how to:
Perform amp testing with a meter & inductive pick-up
Test computer modules and sensors
Use an ohmmeter for continuity and resistance checks
Trace current paths and diagnose shared current-path problems
Test fuel pumps and fuel injectors
Inspect fuses, fusible links, and circuit breakers
Test generators and alternators
Diagnose relays correctly
Test starter motors
Evaluate battery condition
Use voltage drop testing to pinpoint faults
Set up meters safely and correctly for any test
Why This Book Matters
Most electrical problems aren’t caused by bad parts — they’re caused by bad tests. When technicians rely on guesswork, they waste time, replace good components, and often never find the true problem. This book solves that. It teaches the shop-proven electrical testing fundamentals Joe Glassford taught for 29 years — the same techniques used by thousands of technicians every day.
Once you understand how voltage, current, and resistance behave under load, diagnosis becomes simple, predictable, and fast — even on modern vehicles.
What Readers Are Saying
“My most used electrical reference.”
“After over 10 years of owning this book, it is far and away my most used reference. I consider it my electrical bible. It has saved me countless hours.”
“Taught me more than school.”
“I’m now not afraid to diagnose electrical problems. You taught me more than my teachers at school.”
“Unbelievably filled with what I need.”
“I haven’t read another book that explains shorts and connections as clearly as yours. The detailed pictures are fantastic. You hit a home run!”
“Transformed me as a technician.”
“Your knowledge has transformed me. Thank you for simplifying concepts that used to confuse me.”
Who This Book Is For
This book is designed for:
New technicians learning electrical testing for the first time
Experienced mechanics who want more reliable diagnostic methods
Students in automotive programs who need real-world techniques
DIY mechanics who want to understand their vehicles better
Anyone who wants to eliminate guesswork and diagnose with confidence