NOTE: Never use a self-powered test light to perform checks
for opens or shorts when power is applied to the electrical system under test.
The 12 volt vehicle power will quickly burn out the light bulb in the test
light.
- Isolate the circuit from power and ground.
- Connect the self-powered test light or ohmmeter ground clip to a good
ground and probe any easy-to-reach test point in the circuit.
- If the light comes on or there is continuity, there is a short somewhere
in the circuit.
- To isolate the short, probe a test point at either end of the isolated
circuit (the light should be on or the meter should indicate continuity).
- Leave the test light probe engaged and sequentially open connectors or
switches, remove parts, etc. until the light goes out or continuity is broken.
- When the light goes out, the short is between the last two circuit components
which were opened.