Basic Knowledge Required

A basic knowledge of the following items is required for use: (Use of the diagnostic procedures 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). Refer to "Troubleshooting with a Digital Multimeter" in Diagrams. 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 Diagrams for a review of basic electrical troubleshooting. General Motors Service Training also offers electrical/electronic courses.