How to Repair Broken Fog Lights

February 17, 2012

Fog lights don’t always require outright replacement when something goes wrong. Find out when you can change the bulb, lens assembly, fuse or switch.

Fog Lights

Fog lights enhance the driver's visibility while driving in bad weather. Two main reasons exist for fog light failure. One is damage to the unit itself and the second could be attributed to an electrical problem.

Your owner's manual can provide the part numbers, information about repairing the components and instruct you on the types of tools needed. Always use replacement parts approved by the car's manufacturer.

You may have to lie on the ground and reach up into the front bumper behind the fog lamp. Some vehicles may have a protective shroud on the underside of the bumper. Remove the retaining screws securing the shroud to the bumper.

Changing the Light Bulb

  • Grab the retainer holding the light bulb
  • Gently twist the retainer counterclockwise
  • Pull the retainer back from the lens assembly
  • Remove the old light bulb and install the new light bulb
  • Reinstall the retainer into the lens assembly
  • Switch on the fog lamps to test the new bulb
  • Reinstall the shroud

Changing a Damaged Lens Assembly

  • Grab the retainer holding the light bulb
  • Gently twist the retainer counter clockwise
  • Pull it back from the lens assembly
  • Remove the lens assembly by removing the retaining screws
  • Put the new lens assembly in the place of the old one
  • Reinstall the retainer into the new lens assembly
  • Reinstall the shroud

Minor Electrical Faults

Changing a Blown Fuse

  • Locate the fuse box. It could be located under the instrument panel and or under the hood. Modern cars have more than one fuse box. Consult the owner's manual to find the correct one
  • Remove the cover from the fuse box
  • Use a fuse puller to remove the fuse. The filament of a blown fuse will be broken
  • Replace the old fuse with a new fuse which has the same amperage rating as the blown fuse
  • Switch on the fog lamps to test the fuse

Replacing a Faulty Switch

  • Disassemble the instrument panel around the switch
  • Pry the switch assembly from the instrument panel or remove the retaining screws holding the switch in place
  • Gently pull the wiring out until the connector appears
  • Unplug the switch from the connector. Check the condition of the wiring while it is exposed
  • Plug in the new switch
  • Switch on the fog lamps for a test
  • Reassemble the instrument panel in the reverse order

Related Questions and Answers

Why Do Fog Lights Have Yellow Bulbs?

Fog lights yellow bulbs are the result of the manufacturer's preference for yellow fog lights, versus the superiority of yellow lighting for fog lights. At one time, it may have been believed that yellow fog lights were superior to other colors, due to the shorter wavelength of the yellow light. (According to a seismologist at the Geophysical Institute at the University of Alaska Fairbanks.) However, this is false. Fog lights of colors other than yellow are available in almost any automotive store. You can buy fog lights with a blueish tint, or with a traditional white lighting color.

Why Do High Beam Headlights Reflect in the Fog?

High beam headlights get their name from their reflection zone. Low beam headlights get their name because the headlights are essentially aimed at the road. You should not use high beam headlights when driving in the fog because the higher level of the beam aims directly at the fog, which can cause the fog to "reflect" back at you. This can further reduce your vision. Low beam headlights, in conjunction with fog lights, if equipped on the vehicle, are the ideal lighting method for fog driving.

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