The indicator light is flashing much faster than usual. What could be the cause of this?

You are correct. If the indicator light is flashing much faster than normal, it usually means one of the indicator bulbs is defective. When a bulb fails, the electrical resistance changes, causing the indicator relay to flash more rapidly. This is a warning to the driver that a bulb needs to be checked and replaced. Faulty fuses or using the hazard lights do not cause the indicator to flash faster. Remember: a fast-flashing indicator signal points to a problem with one of the indicator bulbs.