If your vehicle is showing turn signal blinks much faster than normal, here are the most likely causes and the parts you'll need to fix each one.
The most common reason for a fast-blinking turn signal is a burned-out bulb on that side of the vehicle. The system is intentionally designed to 'hyperflash' to alert the driver that a bulb needs replacing.
If you recently installed aftermarket LED turn signal bulbs, they draw significantly less power than standard incandescent bulbs. The vehicle's flasher relay interprets this low power draw as a burned-out bulb, causing hyperflashing unless a load resistor or LED-compatible relay is added.
Moisture and dirt can cause corrosion inside the bulb socket, preventing a solid electrical connection. Even if the bulb itself is good, the poor connection stops current flow, tricking the system into thinking the bulb is dead.
The flasher relay controls the blinking rhythm of your turn signals. If the internal bi-metallic strip or electronic circuitry begins to fail, it can cause the signals to blink erratically or at double speed.
In rare cases, the electrical contacts inside the turn signal stalk on the steering column can wear out or short circuit, leading to irregular, rapid, or continuous flashing.