Both fog lights and driving lights supplement the amount of visibility your headlights produce in various driving situations. To help increase visibility in foggy conditions, fog lights emit a wide beam to help the driver see more of the road. Driving lights can be particularly helpful by adding more light to a particularly dark and unfamiliar road. When the fog and driving lights fail, drivers may struggle to readjust to the standard high beam/low beam headlights.
How this system works:
When a driver wishes to use their fog or driving lights, they engage a switch in the cabin which indicates to a relay that the lights should be turned on. The relay then transfers power from the battery to power the lights. Fuses keep electrical components on the vehicle from overloading the system and will blow or break the connection when they sense a problem.
Common reasons for this to happen:
Blown Fuse: As a first resort, many mechanics will inspect your fuses in the event an electrical component, like the fog or driving lights, fails. When a fuse blows, it prevents the circuit from completing and will not allow the lights to turn on.
Burned-out Bulbs: Over time, bulbs will wear out and will stop working. A good indication that a bulb has burned out is if only one light is out and the other light is functioning properly. If a bulb burns out, it typically will not affect the rest of the electrical system, allowing other bulbs to function normally.
Bad Relay: A relay transfers power from the battery to the lights themselves, but when a relay fails, the connection is unable to be completed. A relay may also fail because it is not grounded properly. A wire that is not grounded properly is unable to protect the circuit and provide an outlet for excess charge that build up. A vehicle with a bad relay or bad ground may not be able to successfully power your fog or driving lights.
What to expect:
A top-rated mobile mechanic will come to your home or office to determine the why your fog or driving lights have failed. The mechanic will then provide a detailed inspection report outlining the nature of the failure and the cost of any repairs that need to be made.
How it's done:
When checking electric components on your vehicle, especially, fuses and relays, the mechanic will bring a multimeter which will help him or her diagnose what specific component has failed. The mechanic will begin by first examining the car to look for any signs of superficial damage (e.g. broken lights, frayed or incomplete wiring). If there is no superficial damage to the car, the mechanic but then begin examining the different components along the electrical circuit.
The mechanic will most likely begin by inspecting the vehicle’s fuses. A typical vehicle has many fuses corresponding to different functions like lights, the radio, and auxiliary power sources. The mechanic will check the fuses specific to the fog and driving lights to ensure that it isn’t blown. If it is, he or she will replace the fuse with another one appropriate for the amperage needs of the circuit.
If the fuses are in good working order, the mechanic will inspected the bulbs in the fog and driving lights to ensure that they are functioning properly. A bad bulb will typically have a broken filament which prevents current from running through the bulb and illuminating the gas inside. If the bulb needs to be replaced, a mechanic will replace it with a bulb that is appropriate for the vehicle.
If the mechanic suspects a bad relay, he or she will find the corresponding relay for the fog and driving lights and use a multimeter to test the resistance of the of the unit. If the relay is not function properly, the mechanic will replace it and ensure that it is wired up properly.
In all cases, the mechanic will be sure to test your lights before he or she leaves to ensure that they are working properly.
How important is this service?
Fog and driving lights provide a driver with more visibility in potentially dangerous situations. Drivers with a greater need for this extra illumination should be diligent when seeking out repairs. A mobile mechanic can replace necessary components so as not to compromise visibility during your commute. It can be difficult for some drivers to adjust to high and low beams exclusively, after regular using fog and driving lights. Having that extra layer of security, the extra visibility, can increase a drivers ability to avoid dangerous situations.