What does a diode check reading of 0.0001 on both sides indicate?

A diode check reading of 0.0001 on both sides typically indicates that the diode is shorted. In a healthy diode, you would expect to see a significantly higher resistance reading in the reverse direction, showing that it effectively blocks current flow in that direction. The low reading of 0.0001 suggests that there is minimal resistance, allowing current to pass through in both directions, which is characteristic of a shorted diode.

Understanding how a diode operates is crucial: it should conduct current in one direction (forward bias) and block it in the opposite direction (reverse bias). The reading here denotes that the diode may no longer be functioning properly and is behaving as if there are no barriers to current flow, hence the categorization as a shorted diode.

Recognizing this difference is important in troubleshooting circuits, as it affects the overall performance and safety of the system in which the diode is used. If the reading had suggested a significantly different value in one direction versus the other, it would indicate a functional diode.