Circuit Inspection: Description

In general, testing electrical circuits is an easy task if it is approached in a logical and organized method. Before beginning it is important to have all available information on the system to be tested. Also, get a thorough understanding of system operation. Then you will be able to use the appropriate equipment and follow the correct test procedure.
You may have to simulate vehicle vibrations while testing electrical components. Gently shake the wiring harness or electrical component to do this.

OPEN	A circuit is open when there is no continuity through a section of the circuit.
SHORT	There are two types of shorts.
	SHORT CIRCUIT	When a circuit contacts another circuit and causes the normal resistance to change.
	SHORT TO GROUND	When a circuit contacts a ground source and grounds the circuit.

NOTE: Refer to HOW TO CHECK TERMINAL How to check Terminal to probe or check terminal.

TESTING FOR "OPEN" IN THE CIRCUIT

Before you begin to diagnose and test the system, you should rough sketch a schematic of the system. This will help you to logically walk through the diagnosis process. Drawing the sketch will also reinforce your working knowledge of the system.

Courtesy of NISSAN NORTH AMERICA, INC.