Basic Knowledge Required

Before using this section, it is important that you have a basic knowledge of the following items. Without this basic knowledge, it will be difficult to use the diagnostic procedures.
If you need a review of basic electrical troubleshooting knowledge, Refer to Electrical Diagnosis Procedures. Additionally, electrical/electronic courses are offered through General Motors Service Training.

Basic Electrical Circuits
^ You should understand the basic theory of electricity and know the meaning of voltage, current (amperes) and resistance (ohms).
^ You should understand what happens in a circuit with an open or shorted wire.
^ You should be able to read and understand a wiring diagram.

Use of Circuit Testing Tools
You should be familiar with the Digital Multimeter (DMM) J 39200, and be familiar with the meter controls and how to use them correctly. You should be able to measure voltage, resistance and current. You should know how to use jumper wires to bypass components for testing circuits.

Important: When measuring the resistance to ground of circuit or component, make sure to use a solid, unpainted chassis ground or the negative battery terminal.