The purpose of the Nissan tail light is to inform divers behind you that your vehicle will be slowing down, turning, or backing up. This electrical component does not improve the performance of the vehicle but is a safety device to help avoid an unwanted accident. Unlike a headlight that must be in working order after the sun goes down, the tail light must be working whenever you are driving your Nissan. That includes daytime, night time, and any time in between. If just one of the tail lights is out or not functioning, then the vehicle is considered to be illegal and can be pulled over by a law enforcement officer who can then issue a ticket. You will have to get this fixed and appear before an inspector or law enforcement officer so they can approve it. In most instances, the failure of a tail light on a Nissan is the filament in the bulb being burnt out. This is an easy and simple procedure to remedy. With a simple twist a new bulb can be put into place and the vehicle made street legal once again. These bulbs can just go bad over time but in some instances the tail light failure can be caused by their exposure to moisture. If the bulb is exposed to moisture then the Nissan tail light assembly should be inspected. The lens could have a crack or break in it that is permitting the entry of this unwanted moisture which in turn shorts out the bulb. By removing the entire assembly from the body of your Nissan, a thorough inspection can take place identifying the faulty part. This will prevent the bulb from shorting out in the future.