Basic Knowledge Required

A basic knowledge of the following items is required for use of this section:
(Use of the diagnostic procedures in this section will be difficult without this basic knowledge.)

Basic Electrical Circuits
An understanding of the following concepts is required:
^ The basic theory of electricity
^ The meaning of the following terms:
- Voltage
- Current (amperes)
- Resistance (ohms)
^ The result of an open or shorted wire in a circuit
^ How to read and understand a wiring diagram

Use Of Circuit Testing Tools
An understanding of the following concepts is required:
^ The use of the J 39200 Digital Multimeter (DMM)
Knowledge of the controls and their correct use is required.

Important: Use a solid, unpainted chassis ground or the negative battery cable when measuring the resistance to ground.

^ How to measure the value of the following items:
- Voltage
- Resistance
- Current
^ The correct use of jumper wires for the following purposes:
- Bypassing components
- Testing circuits
Refer to General Electrical Diagnosis Procedures in Diagnostic Aids under Diagrams for a review of basic electrical troubleshooting knowledge.
General Motors Service Training also offers electrical/electronic courses.