Motorcycle drivers are less protected than other motorists on the roadway. Some riders choose to announce their presence through what appears to be blinking lights. In fact, a common piece of motorcycle equipment causes the effect. Blinking may also occur if the motorcycle headlight has a problem, such as worn wires or a blown fuse.
Headlight Modulator: Motorcycle lights that appear to blink likely have headlight modulators installed. A 2000 federal law made modulators legal in the United States. The equipment does not actually blink on and off. Instead, the headlamp's intensity varies, which creates a flashing effect.
Safety: Some motorcycle owners use so-called blinking headlights for safety. Motorcycles are smaller than most vehicles on the road, and have only one headlight to warn motorists of the motorcycles' presence. The blinking effect from headlight modulators catches other drivers' attention, and may encourage them to be more mindful that a motorcycle is in the vicinity.
Electrical Problems: Some cases of blinking motorcycle headlights could be caused by an internal problem. A modulator would not turn the headlight off and on. If this occurs, unsnap the headlight and look for damage. A wire could be loose, unplugged or frayed, or you could have a blown fuse. Inspect the bulb for signs of a bad filament. If your motorcycle headlight is blinking without use of a modulator, replace the light or see a professional mechanic to diagnose the problem.