When testing a capacitor, if the capacitor is functioning properly, it will exhibit a consistent high resistance reading. This high resistance indicates that the capacitor can hold charge effectively and does not have any internal shorting or significant leakage. A good capacitor charges and discharges slowly, leading to a gradual decline of current when initially charged, but eventually, it stabilizes at a high resistance level after sufficient time.
This characteristic is vital because an ideal capacitor will act as an open circuit after it is charged, preventing a continuous flow of direct current, while still allowing alternating current to pass depending on frequency. Therefore, the presence of a high resistance reading is a key indicator that the component is in good condition and aligns with expected behavior in normal capacitive operation.