Operation CHARM: Car repair manuals for everyone.

Test-Lights

Non-Powered Test Light:






TEST LIGHTS
Two types of test lights, the circuit powered test light and the self-powered test light, are commonly used to test automotive electrical circuits. Both test lights are usually referred to as 12-volt test lights.

CIRCUIT POWERED TEST LIGHT
Uses vehicle battery or circuit voltage, to light the test lamp.

Use to check for power or ground.

Verify lamp operation, before using, by connecting the clip to one battery terminal and touching the probe to the other battery terminal. The test lamp should light.

SELF-POWERED TEST LIGHT
Uses an internal battery to light the test lamp when continuity exists between the test probe and the clip.

Use to check circuit opens or shorts.

Before using, verify operation by connecting the clip to the test probe: the test lamp should light.

CAUTION: DO NOT connect a self powered test light across a 12 volt circuit. This will burn out the bulb.