Horn circuit failure analysis? Common faults of car horns

What are the reasons why the horn does not sound, and how to diagnose and analyze:

1. The reason why the horn does not sound:

Faulty fuses, horn switches, horn relays, lines, horn itself.

2. The methods of fault diagnosis and elimination are as follows:

1. Check whether there is electricity in the live wire. Use a screw to scrape the horn relay "battery" binding post with the grounding iron. If there is no spark, it means that there is an open circuit in the live wire, and whether there is an open circuit between the battery fuse and the "battery" binding post of the horn relay should be checked.

2. If there is electricity in the live wire, then use a screw to short-circuit the two binding posts of the "battery" and "horn" of the horn relay, if the horn still does not sound, it means that the horn is faulty; If the horn sounds, it means that the horn relay or button is faulty.

3. Press the horn button and listen to whether there is any sound in the relay. If there is a "rattling" sound (contact closing) but the horn does not sound, it means that the relay contacts are oxidized or ablated. If there is no "gurgling" sound reaction in the relay, then use a screw to short-connect the horn button binding post with the grounding lap iron, if the relay contact is closed and the horn sounds, it means that the button is oxidized, rusted or dirty and has poor contact; If the relay contacts still do not close and the horn still does not sound, it means that there is an open circuit in the relay coil.

4. Press the button, the horn only makes a "ho" sound and then it does not sound, this fault is inside the horn, you can remove the horn cover and then press the button to observe whether the horn contact is open. If it can't be opened, it should be readjusted; If it can be opened, check the contact gap and whether the capacitor or arc extinguishing resistor is short-circuited.

5. If the horn of the button does not sound when pressed, check the circuit and find that the fuse jumps (or the fuse blows), first of all, check whether there is a short circuit fault such as a tie in the circuit. The method is to string a test lamp at both ends of the disconnected fuse, if the test light is on, there is an iron place in the circuit from the fuse to the horn relay; If the test light is not on, you can press the button again, if the test light is on again at this time, there is an iron tie in the circuit from the relay to the electric horn, and then use the circuit breaker method to find the tie iron part for investigation.

Hello. This is the circuit diagram of the horn on the car, and most cars look like this. Don't think this circuit diagram is simple ,..

First of all, we have to find the starting point, otherwise we can only look at the car and sigh in the face of failure. Troubleshooting analysis ideas:...

What we have to do in the actual repair is:

Check whether the fault really exists. Nowadays, there are more and more functions in cars, and there are many novice drivers who may not necessarily use the functions in the car, so we must first confirm the fault.

First, observe whether there is any abnormality around the fault. The horn is constantly vibrating, so there is a high chance that the connected harness connector will fall off.

The horn doesn't sound? Or hoarse? Or is it one ringing and one not ringing?

Use a test lamp or multimeter to test whether the horn plug has a power supply and check whether there is a tie! You can fly the wire to find out whether the horn and the line are normal, and you can replace the airbag hairspring! Better repairs without airbags!

1.The horn doesn't sound?

When the horn button is pressed, the reasons why the horn does not sound include button contact ablation, poor contact, poor contact of relay contact, lead detachment, and fuse.

Causes such as burnout and internal defects of the electric horn should be investigated one by one.

2.The electric horn rings often.

The common reasons why the electric horn often rings are the stuck button, the ablation of the relay contact, and the lapping of the relay button wire. In case of frequent ringing failure, the horn fuse should be pulled out in time to stop the long-honking phenomenon, and then check according to the above reasons.

3.Speaker pitch change.

The common phenomenon of speaker pitch change is that double tone becomes single tone, and this fault can be adjusted and replaced as long as the reason for the single non-sound is found.

1) The electric horn does not sound. The reasons include the detachment of the lead wire of the electric horn binding post, the corrosion in the button switch, the bending of the horn button contact or the failure of the spring, and the failure of the electric horn itself.

Car horns not only warn passers-by and vehicles, but also play a vital role in driving safety. But many car owners don't know about some common faults of car horns, so I will introduce them to you one by one here, I hope it will help you.

1.Sometimes the horn doesn't go off.

Some car owners will find that the car horn sometimes rings and does not sound, in fact, this is mostly because of the poor internal contact of the horn switch, of course, it may also be because the horn itself has some quality problems.

2.The horn is hoarse.

The function of the horn is to warn others, which must be loud, if its voice is hoarse, it cannot cause pedestrians and vehicles to pass. Note that it is also easy to cause traffic accidents. The hoarse sound of the horn is mainly due to the poor contact of the horn terminals.

Frequent and long-term honking will cause the horn to be electrocuted and ablated, resulting in impedance, which will weaken the current of the electromagnetic coil and reduce its magnetic force, so that it does not have the attraction to vibrate the diaphragm, resulting in a hoarse sound.

3.The horn is completely silent.

This is a sign that the horn is "terminally ill". At this time, you can check whether the horn fuse is blowing, use a multimeter to measure whether there is electricity here when pressing the horn switch, and adjust the adjusting nut on the horn to see if it can make sound. If the answer is no, then hurry up and buy a new one.

The horn doesn't sound? Abnormal or hoarse voice.

Excessive power consumption and horn, relay failure, etc.

The six reasons for the failure of the car horn are poor contact of the electromagnetic coil terminals, poor sealing, susceptibility to moisture, blown fuses, damaged horns, and contact ablation.

The electromagnetic coil terminals inside some horns are not connected by welding, but are connected by aluminum rivet crimping. If the insulating paint on the enameled wire at the end is not well treated, or the rivet crimping is not firm, it is easy to have poor contact (false connection), so that the car horn is not effective.

Although the inside of the horn is sealed, if the seal is not tight, if the fog enters the car when washing the car or there is water vapor in the air in the internal space, the water vapor can easily cause the contacts to be damp and cannot work normally.

Horn retarded

The failure of the car audio speaker may also be a combination of the above two ways, such as the power amplifier suddenly outputs a large instantaneous energy, this energy can be the sound suddenly turned on, the horn will have a strong vibration, so that the coil is out of the magnetic gap, when it goes back, it may be eccentric and can not return to the original position.

The coil double leaves the magnetic gap, because the magnetic gap is the best heat dissipation environment for the coil, but the coil has left the magnetic gap, then when the coil continues to receive the signal from the power amplifier, the coil will soon heat up and cause the coil to burn, but now this situation is relatively rare, because the current horns are all long-stroke design.

The buried base of the background broadcast is almost a constant voltage transmission system, which is different from the constant resistance system that we usually have more contact with. The output voltage of the constant voltage power amplifier is fixed, divided into 70V, 100V and so on. Each horn is equipped with a line transformer, and the input impedance of the transformer is very high.

This makes it convenient to connect more speakers in parallel on the road. After the system design and installation is completed, it is generally not possible to connect more horns in parallel on the road, so that the resistance of the entire line will not drop. It's okay to hang up your horn less.

The amplifier has four outputs, which can be easily used for zonal broadcasting (can be divided into four zones). Once the decoration causes a short circuit in the line, the consequence is to burn the power amplifier. So, 1

The construction crew must be asked to ensure that the circuit is not damaged (signed); 2.The line to the partition of the renovation area was temporarily stopped. As for the line short circuit check, we only need to measure the resistance at the power amplifier end.

If the resistance of a certain circuit is measured to be a few ohms or ten blades, the circuit will have a short circuit, because under normal circumstances, the line resistance is very large.

1. Loose sealing is susceptible to moisture: Although the inside of the horn is sealed, if the seal is not tight, if the car is not tightly sealed and enters the fog or there is water vapor in the air in the internal space, the water vapor can easily cause the contacts to be damp and unable to work normally.

2. Poor contact of electromagnetic coil terminals: some horns internal electromagnetic coil enameled wire terminal joints are connected by aluminum metal rivet crimping, non-reliable welding connection, if the insulating paint on the end enameled wire is not clean or the rivet crimping is not reliable, it is easy to produce virtual connection faults, resulting in poor horn work. This kind of failure is the quality of the horn, which cannot be repaired, and can only be replaced with new parts.

3. Contact ablation: If the horn is pressed for a long time, it is easy to cause the horn contact to be ablated and the impedance will be generated, the current flowing through the electromagnetic coil will be weakened, and the electromagnetic attraction will not attract the armature to drive the diaphragm to vibrate normally, resulting in hoarse or even no sound. However, when the horn is constantly pressed, if the instantaneous strong current passes through the impedance, it can still work normally, so it will be good and bad.

The car horn does not sound and is divided into several situations, one is that it does not sound sometimes, one is that the sound is awkward, and the other is that the car horn does not sound at all.

1.Sometimes it doesn't sound. Press the horn switch, if the horn sometimes rings, sometimes it doesn't, most of the contacts inside the horn switch are not in good contact, and some are also the problem of the horn itself.

2.Hoarseness. It is mostly due to poor plug contact, especially the various contacts around the steering wheel, which are prone to wear and tear due to frequent use.

3.Not at all. First, check the fuse to see if it is blowing, then unplug the horn plug, and use a multimeter to measure whether there is electricity here when the horn switch is pressed.

If there is no electricity, the speaker harness and horn relay should be checked; If there is electricity, it is a problem with the horn itself, at this time, you can also try to adjust the adjusting nut on the horn to see if it can make a sound, if it still does not sound, you need to replace the horn.

Auto repair experts say that in the failure of car horns, it is often the fault of the horn itself when there is a problem. When the horn does not sound, there are no more than 3 common fault parts, namely the horn itself, the horn switch contact and the horn wiring harness, when the car horn fails, it can be solved according to the above classification. I really can't solve it, so I recommend going to a car repair shop.

1.The horn doesn't sound?

2.Abnormal or hoarse voice.

3.Excessive power consumption and horn relay failure, etc.

1. Common faults of horns.

1.Contact ablation: If the horn is pressed for a long time, it is easy to cause the horn contact to be ablated, resulting in impedance, and the current flowing through the solenoid coil will be weakened.

Electromagnetic gravity does not attract armature to drive the diaphragm to vibrate normally, resulting in hoarse or even silent sound. However, when the horn continues to sound, it can still work normally if an instantaneous strong current passes through the impedance, so there will be ups and downs.

2.Poor sealing is easy to get moisture: Although the inside of the horn is sealed, if the car is washed without tight sealing, the inside of the horn enters the fog or there is water vapor in the air in the internal space, and the water vapor can easily make the contacts damp and unable to work normally.

3.Poor contact of solenoid terminals: Some terminals of the magnet wire of the solenoid coil inside the speaker are connected with aluminum metal rivets, and the welding is not firm.

If the insulating paint at the end of the enameled wire is not clean or the rivet is not pressed firmly, it is easy to cause false connection faults and cause the speaker to work poorly. This failure is caused by the quality of the horn, which cannot be repaired and can only be replaced with new parts.

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The horn doesn't sound? Press the horn button, the reasons why the horn does not sound include button contact ablation, poor contact, poor relay contact contact, lead detachment, fuse burning, electric horn internal adverse reactions and other reactions, which should be investigated one by one.

The common reasons for the frequent ringing of the electric horn are the button stuck, the relay contact ablation, the relay button lap iron, in case of frequent ringing failure, the horn fuse should be pulled out in time to stop the phenomenon of long beeping