Using turn signals is simple enough, just flick a lever by the steering wheel in the direction you want to go and everyone behind you will know what you're planning. However, if an exterior light bulb burns out or other issues arise, the system may not function properly. You might think that the driver behind you knows you're going to slow down, but he could wind up rear-ending you if your blinker isn't working properly. This is why the car is equipped to alert drivers when a bulb goes out.
When a turn signal blinks more rapidly than it's supposed to, this can mean that one of the light bulbs has burned out and needs to be replaced. It is important to do this as soon as possible so other drivers will know what you're up to on the roadway. A burned-out light can also result in a citation that will cost a lot more than a new light bulb.
After you've noticed that the turn signal indicator is flashing faster that usual, you'll need to determine which bulb is out. Park the car and shut the engine off (to save gas), but leave the ignition in the "on" position. Activate the blinker, hop out of the car and look for the missing light.
When you find it, shut the car off and replace the bulb. This process can be simple in many vehicles, but it may be a bit more complicated for some models. The owner's manual will provide assistance with replacing exterior bulbs. After this is done, test your signal out. If it's still not working, the ground circuit could be busted. In this case you'll have to replace the bulb socket.
If none of the lights are out, but the dash indicator is still flashing too fast, there may be a problem with the flasher unit. This component of the lighting system is responsible for interrupting the circuit that activates the light to make it turn on and off. When the flasher unit fails, it will need to be replaced.
Turn signals are one of the only ways that drivers have to communicate with one another on the road to avoid accidents. Technology is being developed to allows cars to "talk" to each other, but until that becomes standard, motorists need to rely on blinking lights to alert others that they are about to change course.