My low beam light doesn't work but high beam does..
Experienced mechanics share their insights in answering this question :
Hello, thank you for writing in. Typically when both low beams go out at the same time, there is an issue with the power supply to them. This means you will want to start by checking the bulbs and making sure they are both perfect. Then check the fuses for all of the headlight functions. If the fuses are good, you will want to turn your attention to the headlight switch, or the dimmer switch if you are equipped with one. Both of them have an effect on the connection to the headlights. The headlights must also be grounded, so make sure the headlight switch’s ground connection is secure and clean. For more diagnostic help contact our service department to schedule an appointment.

How to Identify and Fix Common car Problems ?

Our sources include academic articles, blog posts, and personal essays from experienced mechanics :

Low Beam Headlights

Unlike high beam headlights, these point down at an angle to better illuminate the road. That`s why low beams are referred to as “dipped beam” headlights in some parts of the world. It also means you can safely use your low beams even in the middle of traffic.

Dipped headlights are the most commonly used headlights; brighter than sidelights, but not as bright as full beam headlights. They get their name as they are angled downwards, towards the road.
Low beams are lower intensity and reach a shorter distance in front of your car. High beams are high intensity and light a greater distance.
Low beam − These are the main headlights designed to illuminate the road directly in front of the car. They shine brightly, but only for a short distance (about 40-50 meters). High beam − The headlights that shine at a long distance, 656-984 feet. They provide a comfortable light path even at very high speeds.
Main beams also known as full beams or high beams should be used only when visibility is low or there is limited lighting on the road. These lights shine forward and up to help you see further ahead. It`s always recommended to use main beams when driving on roads with no streetlights to illuminate the entire road.
H7 bulbs tend to be used for dipped – or low – beam, while H1 bulbs can be high or dipped beam, depending on output. Other H-rated bulbs can be used for fog lights and indicators – your Haynes Manual will tell you which bulbs your car uses, along with the watt rating for each.
A max of two, front-mounted fog lights are allowed. They can only be used with low-beams, not your high-beam headlights. They must be white or amber.
High-beam headlights shine at an angle to illuminate the road 350 to 400 feet ahead or about twice as far as low beams. (Remember that 68 mph equals about 100 feet per second.
: a vehicle headlight beam with a long-range focus.
Generally, you`ll have a standard halogen bulb for low beams, and then an HID bulb for your high beams. These are not interchangeable. Both require a different bulb (HID bulbs are significantly more expensive than halogen bulbs, as well).
Whether an LED headlight—which consists of multiple LEDs—is set to low beam or high beam is dependent on the number of lights that are shining. When set to low beam, the individual lights of the LED will adjust to create a defined line so there is no light coming out above the beam.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

Headlight Issue
ANSWER : Hello.

The daytime running lights are not supposed to function at the same time as the headlights. The daytime running lights are only supposed to come on during the day, to provide additional visibility for daytime driving, independently of the headlights. When the headlights are turned on the daytime running lights should turn off. If they are not turning on it may be possible that perhaps the bulbs have burned out, or there is an issue with the fuse or relay. If you run into any issues, consider contacting a certified technician, like one from YourMechanic, as certified technician can diagnose any issues with your lights firsthand and help you make the right repair.

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My headlights came on and drained my battery I put a new battery in and my headlights still wouldn’t go off I took out the bulb an
ANSWER : The common thread between the headlights and the signal lights is the combination switch. The combination switch controls your signal lights, turns the headlights on and off, as well as controls the high beam function. Most like;y the switch or wiring to the switch has an electrical short. This can cause constant power going to the functions the switch controls. While the combination switch is the most likely cause, wiring can also be a problem so I suggest having a certified technician look into the lights staying on to determine if there is a wiring issue before replacing any components. If the combination switch is found to be the culprit, the technician can replace it for you.

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I turn my high beam headlights on and both headlights go out.
ANSWER : Hello, thanks for writing in about your Nissan Frontier. The only way to tell if it is the light bulbs or the switch is to check for power to the bulbs when you switch to high beam. Most of the time both bulbs are bad. The connections to the bulbs could be faulty as well. If you’re unable to pinpoint the issue, have a certified technician, like one from YourMechanic, diagnose your lights firsthand for an accurate repair.

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I changed the lightbulbs on my cars headlights but the driver side headlight won’t turn on…
ANSWER : Hello. Ironically, I happen to have a 2000 CLK 430 as well and I experienced an almost identical scenario as you did. I had a fog light out on my vehicle, thinking it was a bulb I went ahead and replaced the light bulb but once I replaced it it still did not fix the issue. Upon further inspection of my vehicle I found that the some of the insulation around the wiring leading to the fog light was brittle and causing wires to be exposed. I taped the wires with some electrical tape because Mercedes-Benz has a very sensitive electrical system and if a wire is exposed it will cause resistance. If the electrical system senses too much resistance it will cut power off to that component to help protect other electrical parts. I suggest to have a technician such as one from YourMechanic inspect the wiring of your fog light that is out, check the fog light fuse in the side fuse compartment, and also check the clearance light bulb. The clearance light bulb is a small bulb located under the fog light and is integrated into the fog light circuit. If the clearance light is out it will interrupt the fog lights power. On my vehicle it was a clearance light being out and the damaged wiring to the fog light causing my fog light to be inoperative. You are able to find a technician and schedule an appointment to evaluate your vehicle here https://www.yourmechanic.com/services/fog-or-driving-lights-are-not-working-inspection

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I need help replacing stock headlights with Halo LED Projector HID headlights.
ANSWER : This is more of an aftermarket-type of repair. You are right about needing 2 more ballasts, and I recommend you get them from the same manufacturer as the kit you have. For this type of modification, consider visiting a local repair shop or contacting the manufacturer of the kit for specific details.

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The headlights wont shut off and the horn keep honking when I turn them on.
ANSWER : It sounds like you have a rubbed through wiring harness or two. All the components you mentioned are switched on the ground side. That means if there is a short to ground on the switch side before the relay, then the light will turn on. This would lead me to think that there is a rubbed through harness in the steering column. This will not blow a fuse though.

The light or horn will simply turn on without you moving the switch. The fuse for the taillights and dash lights is a different concern. A short to ground on the positive side, after the relay will blow a fuse. It will only blow the fuse when it is switched on. This could mean a short in any positive wire in the taillight circuit. There are a lot. Every switch that illuminates when you turn your parking lights on could be shorted. Any taillight or parking light circuit, too.

Here are some tips. There is only one way to find this type of problem – it will have to be visually traced. Follow the harnesses with your eyes and look for damage. Use the clues that the car is giving you to narrow your search. The wires will need to repaired after the problem is found. If you need help having this diagnosed and repaired, a certified technician from YourMechanic can inspect your electrical system and let you know what fixes need to be performed.

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What is the second switch called on my headlight switch?
ANSWER : Hi there. The second switch on that turn signal indicator is the parking lights. However, I understand what you’re thinking about doing and would highly recommend purchasing a detailed wiring schematic for your Mitsubishi or a repair and service manual first. Many people attempt to do this and end up calling a mechanic to rewire their accessory system due to an electrical fault or the wrong wires hooked up. Proceed with caution or have a local professional mechanic or car audio / alarm company provide you with the detailed instructions to complete this project.

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My headlights do not turn off
ANSWER : Your vehicle is probably equipped with daytime running lights, whereas the other car you saw was not. On your vehicle, these lights will stay illuminated regardless of whether the exterior light switch is in the on or off position. There is no way for the driver to disable this system. In theory, a mechanic could re-wire your system to prevent the lights from turning on, but that would be costly and may be against the law in some states. My advice is to just accept the daytime running lights for what they are.

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