Major Causes of Faulty BMW 325i Tail Lights
Your BMW 325i tail lights are very important when it comes to guaranteeing your safety on the road, but they can't do much protecting once they stop working. Defective tail lights can lead to traffic violations and accidents, so fixing them as soon as possible is a must. Here are some of the possible reasons behind your malfunctioning tail lights:
Burned-out tail light bulbs
Faulty bulbs are the most common causes of tail light failure. Your tail light bulbs normally need replacement after several years of use, but you might have to resolve other issues with your tail lights if your burned-out bulbs are relatively new. Examine your bulb sockets and make sure that they are free of rust. It would also be a good idea to check for any cracks on the lenses that might be letting moisture into your tail light assembly.
Blown fuses are also a major culprit behind tail light failure. If you noticed that both of your tail lights stopped working at the same time, there's a big chance that a damaged fuse is the root of your problem. Check the fuse located behind your car's glove compartment and replace it if it's damaged.
Loose wiring connections, broken wires, and corroded wires are also very common reasons behind blown tail lights. Although fixing these electrical issues in your Bimmer is best left to professionals, you can try diagnosing the wiring issue first using your car's service manual. Check the wiring diagram for your car's tail lights and see if you have some faulty or loose connections. You can also do a voltage test using a digital ohmmeter or multimeter to see if your wires are able to deliver consistent power to your tail lights.
Other troubleshooting reminders
A close inspection of faulty tail light bulbs can also give you some clues regarding the exact nature of the problem. Bulbs that fail due to old age usually have a dark metallic sheen, while bulbs that are blown due to a poor seal typically have a black, dirty appearance. If the reason for your failed bulbs are broken or stretched filaments, your tail lights were probably subjected to too much shock or vibration.