What You Can Learn from Joe Glassford’s Book

Understanding & Troubleshooting Vehicle Voltage Drop Book By Joe Glassford

A book that gives real world explanations as to what is happening in circuits when they suffer from a voltage drop that causes electrical and electronic components to stop working as engineered. This book takes the mystery out of voltage drop. It looks at Ohms Law without complicated math, and provides a refreshing approach to a complex subject. If you are a little rusty on the subject of voltage drop, and what can cause electrical or electronic components to stop working as designed, this is the book for you.

If a component (circuit load), or a current path between either battery terminal and the component is not performing as engineered, more often than not, a voltage drop is the cause; and the results can be as severe as a no crank-no start, or they can be intermittent and rather subtle. This book gives you answers as to what causes voltage drops, and explains how to find those causes.

Experience has shown me why some factory troubleshooting charts give incorrect results, as well as why a technician could put a new electrical or electronic part on a vehicle, only to find out it too does not work. Both situations occur due to a misunderstanding of any one of three key elements in electrical / electronic troubleshooting: (1) how resistance that causes voltage drops in a current path affects the circuit load/s (component/s), (2) how resistance in shared current paths, “the vehicle base system”, can affect totally unrelated circuit operations, and (3) how the volt-ohm-meter reacts to resistance in an open circuit. My experience is shared in this book.


One of the most rampant electrical maladies showing up in automotive service bays today is the phenomenon known as voltage drop. Left unchecked, voltage drop causes countless unsolved electrical mysteries, especially when it infects the ground side of a circuit. It can also trick you into replacing parts that are not bad. The more connections and wiring a vehicle has, the more vulnerable the electrical system is to voltage drop. …

Application Note From the Fluke Digital Library @ www. Fluke.com/library. Diagnosing Voltage Drop: Electrical automotive troubleshooting:

Fluke Corporation P.O. Box 9090, Everett, WA 98260 Used with permission from Fluke.

This book takes the mystery out of voltage drop.

What you can learn from my book:

What voltage drop is and what causes it.

How engineering uses “engineered voltage drops”.

Why resistance and voltage drop are the major “trouble” in troubleshooting.

The limitations of the voltmeter and the ohmmeter.

How to do effective voltage drop testing.

Why good “continuity” never means “able to pass current”.

Cautions about open circuit voltage testing and continuity testing.

How shared voltage feed and ground return current paths affect troubleshooting.

Why resistance that is large enough to cause a problem in a circuit is an elusive value.

How to test your meter to see if it can provide you with accurate results.

Learn why it is smart troubleshooting to do complete shared current path base system tests

on every vehicle exhibiting drive ability symptoms that cannot be pinpointed with scan testing and code retrieval.

See why individual circuit testing should never be performed until after all base-system testing has been completed, and all excessive voltage drops in the base system have been reduced to an acceptable standard.

You will learn how to improve your troubleshooting.

$49.95 include shippping


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