the lights on a vehicle have three purposes – to allow you to be seen, to allow you to see and to give other road users a signal of your intentions.
the different types of lights on a car
up front, there are usually five types of light. the sidelights which can be used when visibility is slightly reduced, but not to the point when dipped headlights are necessary.
You're reading: Understanding different types of car lights
in recent years, these have been replaced on new cars by daytime running lights (drls), which are illuminated as soon as the vehicle’s ignition is switched on, and are only extinguished when the dipped headlights are activated and, sometimes, when you turn on an indicator.
the dipped headlights are next, and should be used when visibility is compromised by the onset of darkness, or by adverse weather such as rain, fog or snow.
full-beam headlights are the brightest lights at the front of the car, and should be used as above and when there is no other road user ahead of you or approaching.
some cars also have a pair of front foglights. these are designed to spread the light beam so it illuminates the edges of the road closer to the front of the car, making it easier to see the kerb in thick fog.
finally, at the front there will be two orange indicators; these flash to let other road users know that you intend to make a turn.
headlight technology is improving all the time, and has moved a long way from the dim bulbs (or even candles!) of old.
many cars now have bulbs filled with xenon gas, which is much brighter than traditional bulbs, and is also less tiring to follow for the driver’s eyes.
however, some manufacturers have moved on, and now offer led headlights, which are brighter and longer-lasting still, yet which consume less energy.
finally, some car makers are now launching laser headlights, which promise yet another step in brightness and efficiency.
at the back of a car are bright red tail lights, which are illuminated when the headlights or sidelights/drls are on. the brake lights are the same red as the tail lights, but are much, much brighter and are only illuminated when you press the brake pedal.
again, a rear foglight helps your car to be seen in fog and heavy rain, while a white reversing light signals to others
who you intend to reverse, and helps you to see behind.
as with front lights, traditional bulbs are being replaced with led technology, which is brighter, more efficient and more reliable.
Read more: 2015 GMC Sierra Headlight Bulbs
how to check the different lights on your car
check all external lights and the horn. visually check all accessible wiring connectors, harnesses and retaining clips for security, and for signs of chafing or damage.
if you need to check your brake lights and indicators unaided, back up to a wall or garage door and operate the lights. the reflected light should show if they are working properly.
if a single indicator light, brake light or headlight has failed, it is likely that a bulb has blown and will need to be renewed. if both brake lights have failed, it is possible
who the switch has failed.
if more than one indicator light or headlight has failed, it is likely
who either a fuse has blown or
who there is a fault in the circuit. the main fuses are located in the engine compartment fuse/relay box on the left-hand side of the engine compartment. unclip and remove the cover for access. in our manuals you can refer to the wiring diagrams at the end for details of fuse locations and circuits protected.
- free haynes online manual preview – take a look inside!
additional fuses are sometimes located in the passenger compartment fuse/relay box. again, your haynes manual or the car’s handbook will tell you where this is.
to renew a blown fuse, remove it, where applicable, using the plastic tool provided or needle-nosed pliers. fit a new fuse of the same rating, available from car accessory shops. it is important
who you find the reason
who the fuse blew.