What is the reason why the rear lights of the P21 5W car bulb do not light up after installing the c

That's true.

Automobile tail lights, including lamps and bulbs in the rear of the car. Among them, one of the functions of the lamp is to aggregate and emit the light emitted by the bulb, so as to enhance the brightness and range of the light emitted by the bulb; The second function is to change the luminous color of the bulb through the color of the lamp. At present, there are three main types of light bulbs, one is halogen car bulbs, one is HID car bulbs, and there are emerging LED car bulbs.

In general, the design of the whole car tail light involves optics, materials science, structure and other disciplines, how to maximize the light effect while taking into account different shapes, lines, and the perfect combination of the car, are testing the ability of designers.

Automobile tail lights include: turn signals, brake lights, position lights, rear fog lights, reversing lights, and parking lights. Among them, some models combine brake lights and position lights, and the bulbs made are double-filament, such as P21 5W bulbs, when the power is 21W when in the state of brake lights, and 5W when in the state of position lights.

The rear fog lights and reversing lights are distributed like this: left fog lights, right reversing lights, that is to say, single fog lights and single reversing lights. The turn signal and brake light are symmetrical, one on the left and one on the left.

1. The bulb is damaged.

2. Poor contact with DU.

3. The power supply line is disconnected.

4. Low voltage.

5. The bulb gauge is wrong.

6. The switch is not connected. The indicator light and shu light when driving are important, especially at night or foggy or dark weather, when the visibility is very low, the light is on or not, it is a sign of safety.

1.If the brake bulb fails, replace the brake bulb.

2.Line fault, check for line problems.

3.Didn't press the brake pedal.

4.If the brake light switch is faulty, replace the brake light switch.

5.Line insurance failure.

There are the following methods:

1. Check the brake light switch.

If there is a problem with the brake light switch, then all the brake lights will not be on, you can use the wire to try to connect the brake lights with a wire, if the brake lights are on, the switch is broken, then buy a brake switch, and replace it.

2. Check the brake bulb.

The frequent use of the brake light will cause the wear and tear of the bulb, the filament of the bulb will not light up after it is broken, when the brake light is not lit in the car, you can observe whether the bulb is in good condition, if you find that the bulb is broken, buy a bulb of the same specification and replace it.

3. Check the fuse.

After the bulb and switch are confirmed to be faulty, it is necessary to check the fuse, some cars do not have a separate brake light fuse, and share a fuse with other electrical equipment, at this time, you can check the working condition of other electrical equipment on the car, check out the electrical equipment that does not work, and replace the corresponding fuse.

4. Check the brake light wiring harness plug.

According to the circuit diagram, find out the plug in the wiring harness of the brake light, open the plug, observe whether the needle angle in the plug is loose or corroded, and repair the corresponding needle angle to solve the fault.

5. Check the brake light and wire.

The tail lights on the car share a tie wire, if the tie wire is broken and falsely connected, it will cause the brake light to not work, so check the tie wire. Once you've found the problem, it's okay to reconnect.

The car brake light does not light up for the following reasons:

If the brake bulb fails, replace the brake bulb;

If the brake light switch fails, replace the brake light switch;

Fault of brake light circuit, check for circuit problems;

Didn't press the brake pedal.

The car brake light is the main warning light of the car, at any time to remind the tail car in front of the state of travel, if the brake light is not lit and not repaired in time, it is very unsafe, it is easy to cause a rear-end accident of the car, I hope that the car friends can get timely repair and troubleshooting when they find that the car brake light is not on.

If the brake light is not on, it will be fined, and the common causes of brake light failure and solutions.

If you step on the brakes during normal driving, the brake light is not lit is the possibility of damage to the bulb, there may be a problem with the brake switch, if there is no scrape line short or open circuit is not very likely, the most direct and best way to replace the bulb treatment.

Most of the reasons are that the bulb is burned, if the bulb is still not lit after a new one, check the fuse, wiring and switch.

The brake switch is broken, the negative electrode is not in good contact or the iron is not good, and the safety is burned.

Such a situation generally occurs at night, because the tail light of the car at night is used to show width, so it must be on, as for the problem that the brake is not lit, if it is said that after stepping on the brake, the brake light does not turn on, and still maintains the original brightness, and the high brake light should be on, then there should be no big problem, if the brake light goes out after stepping on the brake, then it means that there is a problem with the circuit board. The circuit problem is not clear, and the result can only be obtained by inspection.

The main reasons that cause the brake light not to light up are faulty brake switch, brake light wiring, brake light bulb, fuse, etc. There is a method here, that is, step on the brake to test whether the brake switch is powered (the brake light switch is located in the position where the foot brake is pressed), if there is no power, it means that the fuse is broken, if there is electricity, it means that the brake switch is broken. If there is electricity, then stick to the circuit and the bulb.

Possibility 1: There may be a short circuit on one side of the line, such as: aging wires, poor joint contact, etc.

Possibility two: Bulb failure. It is possible to replace the bulb with a new one.

Hello, it is recommended to check the brake switch problem and the line problem I hope my answer can help you I wish you a happy car! [If you have a problem with the car, ask the car master.] 4S shop professional technician, 10 minutes to solve. 】

Hello, the brake light does not light up for several reasons, the brake switch. Line. Bulb. Insurance.

You can step on the brake test switch two wires, there is no power is the insurance is broken, one is electric, the brake switch is broken, there is electricity, check the line, and the bulb.

One does not light up the bulb, and the other does not turn on the brake switch, and then check the circuit.

There are many varieties of this, as follows:

1. If the brake bulb fails, replace the brake bulb.

2. If the line is faulty, check the line problem.

3. Didn't press the brake pedal.

4. If the brake light switch is faulty, replace the brake light switch.

There are two main reasons why the lights do not light up when the vehicle presses on the brakes. First, the most uncomfortable thing is the circuit problem. Today's cars are becoming more and more intelligent and humane, but their internal circuits are also becoming more and more complex.

If there is a problem with the electrical circuit, it must be repaired by a professional, and it is important not to see a doctor in a roadside shop. Second, the life of the lamp has reached its maximum end. The quality and usage habits of the lamp directly determine its lifespan.

No matter what kind of lamp, it is electric heat and luminescence, which is inevitably accompanied by oxidation, although it is filled with inert gas protection, but it will also have an impact over time. In either case, the owner is not allowed to disassemble it by himself, and the operability is basically non-existent. Pure hand-playing, I hope it can help you, hope to adopt.

The lamp beads are off, and the lamp beads need to be replaced.

Bulbs, wiring, switches, fuses.

In this case, it is generally the failure of the bulb of the tail light that does not light up, and the probability of failure of the line is relatively small.

On the premise of checking to make sure that the bulb is not burned out, the main check whether the lamp holder is burned out, the probability of basic circuit problems and fuse failure is small, and finally check the circuit if the lamp holder is burned out.

Two possibilities. It's the bulb that's broken.

The bulb is fine, that is, the fuse is burning.

1. First of all, most of the headlight bulbs of the car are halogen lamps, the light emitted by this bulb is generally dark yellow, the brightness is low, we can replace the brightness of the bulb 2, the bulb is divided into models, some models of bulbs do not have a brighter bulb, we can add a group of xenon bulbs, the light emitted by the xenon lamp is white, so that we will feel brighter, and the light of the xenon lamp is brighter. 3. Now the headlights of the vehicle are also divided into two kinds of lenses and no lenses, the headlights with lenses are generally equipped with ordinary lenses, the role of this lens is relatively small, sometimes the xenon lamp will feel not very bright, at this time we can upgrade the headlights, and there will generally be a repair shop dedicated to headlight upgrades. 4. There is also a headlight without a lens, such a light is worse than the brightness of an ordinary lens, we can add a lens, and then add a set of xenon lamps after installing the lens, so that the brightness of your headlights is absolutely high.

On the one hand, the tail light of the car does not light up due to the ablation of the tail light bulb, and on the other hand, it is caused by the short circuit, open circuit and fuse fault of the control circuit of the tail light and the fuse in it. Of course, it is also possible that there is a problem with the control switch. Hope to adopt, thank you.

Reasons why the rear tail lights of the car do not light up:

1. A blown fuse usually causes both indicators to go out. However, on new cars, the taillights can be melted separately. Check your owner's manual to determine the location of the fuse box in the car.

On older models, the fuse box was usually located under the dashboard. On most new cars, it's under the hood or on the dashboard. The manual will have a ** labeled fuse box showing which fuse is which;

2. Turn off the ignition switch, remove the fuse box cover, and find the tail light fuse. Check the fuse to determine if the fuse is blown. If the metal sheet inside the tail light fuse is intact, it is not a problem with the fuse;

3. If the wire looks broken or looks strange, it means that the fuse is blown and needs to be replaced. Remove the fuse with your fingers or tweezers. Use the search engine to find out what model it is, and then buy one yourself and replace it.

Question: Use a hand-cranked trunk to light up the wires, and then they won't light up again.

Halogen lamps are replaced with bulbs.

LEDs can only be replaced with assemblies.

Analysis of car rear taillights not lit:

1. Overhaul. 1. The rear tail light filament is burned out, and the rear tail light bulb is replaced.

2. The rear tail light is bad, and the rear tail light is repaired.

3. If there is a fault of the rear tail light line, use a multimeter or test lamp to check the circuit opening part of the line, and connect it well.

2. Reasons: 1. The bulb is damaged.

2. Poor contact with contact.

3. The power line is disconnected.

4. Low voltage.

5. The bulb specification is wrong.

6. The switch is not connected. The indicator lights and lights of the car lights are important when driving, especially at night or foggy or dark weather, when the visibility is very low, the lights are on or not, which is a sign of safety.

The car tail light is generally not lit for the following reasons: 1. Check the bulb first, if the bulb is broken, you need to replace the bulb; 2. Then check the line to see if it is caused by a short circuit in the line; 3. Finally, check whether the safety line is disconnected, if so, you should go to the repair shop to replace it.

There are many reasons why the car tail light does not light up, such as the bulb is burned out, the wire is heated, the relay or combination switch is damaged, the wire is open, the fuse is damaged, the contact is poor, etc.

The specific situation needs to be checked by a professional.

It is possible that the fuse is blown out or the bulb is damaged.

To signal vehicles and pedestrians from behind, the tail lamp shades are designed to be red, yellow, and white.

If this is the case for you, it is important to check whether the line connection bulb is damaged, you can refer to it.

Analysis of the reasons why electric vehicles do not go away when there is electricity, and maintenance of line faults.

What kind of light are you talking about? Is it a brake light or a turn signal or a small headlight? Generally, the light does not turn on because of poor contact or fuse burnt out, yo IU is the bulb burned, and you can ask me any questions, or go to the repair shop and 4S shop for repair.

If the tail light is not lit, it may be that the bulb is broken, and if the bulb is fine, it means that the fuse is burned.

Reason: Open circuit.

Mostly because the bulb is broken, replace it with a new one. If the bulb isn't broken, it's time to check the wiring.

The rear lights of the car are not lit can be ruled out as having nothing to do with the lights, and there are 2 possibilities.

1. Fuse ablation, better maintenance method fuse.

2. If the wiring harness is in poor contact, check whether the wiring harness is firmly plugged in. Repair method: Replug the plug connected to the rear tail light cable.

It may be that the insurance is skipping or the line is a problem, hurry up to repair, the tail light is not lit and it is easy to chase the tail, harming others and yourself.

If the tail lights are not lit, it should be a short circuit in the wiring harness, and the line in front of the car should also be checked from the tail light plug.

Hello. Check to see if the insurance burns. Hope it helps.

If you can start driving, it is the failure of the main insurance of the headlights.

Depending on what kind of car you are, some cars have separate high beams and low beams, and some are integrated.