How to Repair Car Lights

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Properly working vehicle lights are an important and necessary security feature. Lights ensure other drivers on the road are made aware of your intentions to turn or slow down, and that your car is visible during low visibility hours.

Traffic laws in all states require working vehicles to repair dead lights as quickly as possible. If not, drivers may be pulled over and issued a mechanical violation or “fix-it” ticket. This is meant as a safety measure to protect drivers on the road.

If your lights aren’t working properly, fix them as soon as you are able. Check out this list of most common car light problems and how you may go about repairing them.

Interior Lights

There are a lot of interior lights, and equally as many interior light problems that could arise. Three of the most common problems include dimming, flickering lights, and lights that won’t turn off.

  • Dim Lights

If interior lights are continuously getting dimmer, it could mean battery or alternator problems. One way to check is to use a multimeter, also known as a multitester. A multimeter is an electronic measuring instrument that takes several types of measurements. They can measure voltage, current, and resistance. Attach one to your vehicle’s battery terminal while the car is on. If the voltage level is low, then the alternator may have to be replaced. For instructions on how to replace the alternator yourself, watch this helpful video. If the voltage measure reads normal, the car’s battery may be dying. Replacing a car battery can be easy, check out this article on how to replace the battery yourself.

  • Flickering Lights

If interior lights are flickering, there may be a few different causes: ground wire problems, dying battery, or a failing voltage regulator. To test for ground wire faults, you will have to use a multimeter to test the voltage. Watch this video on how to detect ground wiring problems. If the problem is loose wiring, it is best to have an auto mechanic safely resolve the issue. Using a multimeter, check for low voltage. If the reading is low, the alternator may need to be replaced. A failing voltage regulator is also a common cause of flickering lights. Using the multimeter, have a friend rev the engine while you keep an eye on the multimeter. If the voltage reads anything above 14 volts, replace the voltage regulator.

  • Shining Light

If the interior light won’t turn off at all, check the switch. Sometimes the switch gets bumped and the lights go in the “on” position. If the light still won’t turn off after being placed in the “door” or “off” position, consult a mechanic.

Exterior Lights

While malfunctioning interior lights could cause strain on the car battery, they most likely will not immediately impact driving safety. But failing exterior lights should be repaired as soon as they are detected. Not just for your safety on the road, but for other drivers as well. So check out these common exterior light problems, and discover how to fix them.

  • Burnt Out Bulb

If the blinkers blink excessively quickly or simply don’t turn on, then you will have to replace the bulb. Thankfully, this is pretty easy to do. The car manual will let you know which type of bulb you need for the exact type of exterior lamp that is failing. The manual will also give detailed instructions on how to replace the bulb. If dealing with high intensity discharge (HID) lights, visit a mechanic as dealing with these bulbs can be dangerous due to their high voltage.

  • Bad Brake Light Switch

Analog switches are responsible for sending a signal that turn the brake lights on. If two or more brake lights are out at the same time, the problem is most likely a bad brake light switch. More often than not, the brake light switch is going to be located under the dashboard. To verify the brake switch location, refer to the car manual. Remove any covers in the way with screwdrivers or a socket wrench. Once the switch is in view and easily accessible, disconnect the power cable connector. Then connect the cable to the new replacement switch, verify it’s secure, and place the switch back in its original location. Replace the covers and you’re done!

  • Blown Fuse

After checking the exterior light illumination and the light switch, the problem may be that the light fuse is blown. Discover where the fuse box is located on your vehicle, and using the fuse diagram found in the car manual, pinpoint the brake circuit. If the fuse is blown, insert a replacement fuse of the same amperage. Easy peasy.

  • Bad Socket

If you only have a single light out, and the bulb is not the problem, check the light socket. If the socket looks dirty or shows signs of corrosion, clean the socket with an electrical contact cleaner. If the wiring is worn, replace the faulty wire.

With the right tools and instruction, you can fix common car light problems yourself. But depending on the problem, it may be beneficial to your safety to have the problem resolved by a proper mechanic.