How can you detect your indicator is defective?

You answered correctly. You can detect a defective indicator if the indicator control lamp flashes faster than normal, since this often happens when a bulb has failed and the circuit changes resistance. It is also correct to perform a functionality test before driving off to ensure your indicators and other lights are working. The control lamp for the indicator is not permanently illuminated red; indicator lamps are typically green, not red. Remember these points to reliably check indicator functions and spot potential problems early.