What indicates a good diode during a diode check?

A good diode during a diode check is indicated when one side reads an open loop (OL) and the other side shows a larger number, which corresponds to the forward voltage drop of the diode. This shows that the diode is functioning correctly by allowing current to flow in one direction while blocking it in the opposite direction.

When testing a diode, the OL reading indicates that there is no conduction in one direction, which is typical for a diode that is healthy. The larger number on the other side represents the forward voltage drop, which can vary based on the diode type but is essential for confirming that the diode is operating as intended.

In contrast, readings such as both sides showing OL would indicate a failed diode that is not allowing any current to pass in either direction. If both sides read a low value like 0.0001, it suggests that the diode may be shorted, allowing current to flow in both directions. Finally, if one side reads 1 and the other OL, it typically does not present a logical forward and reverse bias scenario that would be expected from a good diode.