While car makers are pouring millions into secondary safety systems, most drivers still rely on basics such as lighting and braking for a safe journey. Headlights illuminate the road ahead and warn of possible hazards and obstacles, brake lights tell others of our intention to slow down or stop, and tail lights warn others of our presence on the road. All lights must be in working order and without visible physical damage. Current laws also state that all new vehicles sold in Canada (as of September 2021) must have tail lights that turn on automatically with daytime running lights.
Tail Lights and Road Safety
Tail lights are the red lights at the back of the vehicle. Most are integrated with the same housing as brake lights, but to differentiate between the two they shine in a less intense red shade, or come fitted with reflective materials to amplify or mute brightness. The function of tail lights in road safety is to inform traffic behind you of your presence, with lights often stretched to the outer edges to signal the type and size of the vehicle. Most car makers will have proprietary designs, so besides differentiating between trucks or sedans, for instance, you can also tell the make and model.
This is important in bad weather, such as storms, fog or heavy snowfall to prevent rear-end collisions. Stats also show that third tail lights higher up have reduced accidents and pile-ups by 5 per cent. Damaged, cracked or lights that won’t come on can be easily replaced with aftermarket auto tail lights in varying lighting tech. This can be a simple replacement that works within OE requirements, or an upgrade with a better build, more brightness, or lower power draw.
How They Work
Car tail lights are connected to the same circuits and relays powering the head and daytime running lights, meaning when these are on, so are the tail lights. Older cars will require manually actuating switches or buttons, but current models include auto-light functions that work with light sensors, such as when entering tunnels or when dusk falls. The only time you’ll need to check that they’re working is when a warning light in the dash comes on.
Common Tail Light Issues
One or both tail lights can fail, even if the brake lights are perfectly fine. In most cases, this is due to blown fuses, faulty bulbs or bad light sockets, and these are simple fixes that most car owners can do on their own. There’s more work if the wiring has failed, or when there are issues with sensors in cars with auto lights.
Fuses are located in fuse boxes near the steering wheel or under the glovebox. To check the light fuse, consult the owner’s manual and use a fuse tester. Replacement fuses are very cheap, and slot in position with a simple click. Similarly, blown bulbs and the rear light housings (from overheating current surges, or bad wire insulation) can be accessed from the trunk and replaced with a new bulb in the type that’s compatible with the car.
Discoloured, damaged or worn sockets are also easy to diagnose and are fixed in the same way (via accessing wiring harnesses and sockets in the trunk). For wiring issues, your best bet is an auto electrician. This can be due to bad batteries, problems with switches, damaged insulation, water ingress, rust damage and more. And if ambient light sensors are the fault, they’ll have to be replaced.
Light Types
There’s higher brightness, improved efficiency, more durability, and a long list of favourable features (colour temperatures, increased heat and moisture resistance etc) in aftermarket auto tail lights. The options here include traditional halogens, LEDs, fibre optics and HID lights.
Halogen
These use a tungsten filament encased in glass filled with inert gas. There’s light when the current heats the filament. Halogen lights are recognizable by their warm, yellowish colour (around 3000K). They’re the cheapest aftermarket option for several reasons. They have the lowest lifespans, hovering between 500 and 1000 hours), the highest power needs, and are sensitive to temperature extremes. If you’re after inexpensive yet decent replacements for older vehicles, choose halogen tail lights.
LEDs
Lighting tech has come a long way in the last few years, and light-emitting diodes or LEDs are now standard in all new cars. They use semiconductor diodes that emit light when current passes through them. LEDs are 50 per cent more efficient than halogens, meaning lower power usage and heat levels and subsequently, longer lifespans. Most are rated for over 50000 hours, are more resistant to heat and moisture and have a more compact design with higher impact resistance. They can also be calibrated to different colour temperatures (between warm and neutral). With higher availability and numerous brands, prices are also more affordable.
Fibre Optic Lights
These use optical fibres to transmit light from the source to the tail light housings. They’re a recent addition, with some of the highest efficiency. A significant benefit is uniformity and consistent brightness, and the ability to tailor light designs for the desired look. The novel tech does have its benefits (low power draw, high durability and versatility) but with fewer options than other types, prices can get high.
HIDs
High-intensity discharge (HID) automotive tail lights were popular a decade ago. They produce light when an electric arc is created between two tungsten electrodes in a glass tube filled with xenon gas. They’re recognizable by the cool, bluish tint and colour temperatures averaging 6000K. The lights are more efficient than halogens, converting roughly a quarter of input current into light, are less susceptible to heat, and are more durable.
Despite the high prices, they’re also known for very high brightness. When choosing your next set of tail lights, consider bulb types, brightness levels, colour temperatures, designs and build, and lights that are compatible with your vehicle in terms of sizes, wiring and fit.