The generator does not give charging: reasons. Why does the generator not charge for the battery?

In the article you will learn about the cases when the car generator does not give charging to the battery. The failure is not pleasant, but it can be quickly eliminated. To do this, it is enough to have in your arsenal a standard set of screwdrivers and keys, as well as a multimeter - a device for measuring electrical quantities (resistance, voltage, amperage). Of course, in the case of certain certain breakdowns, you can even limit yourself to visual diagnostics. But everything will be told a little later. And now it's time to find out how the car generator is being dismantled. After that, his disassembly and diagnostics of all the nodes will be considered.

What if there is no charging?

So, you found that the car generator does not give charging. Immediately it is necessary to look for the root cause of this failure, because you can get to the point where the engine simply refuses to work, since it will not be enough for electric power. Consequently, the capacity of the battery is reduced , hence the impossibility of scrolling the starter during engine start-up. Please note that if the generator is completely functional and works in perfect mode, you do not need to charge the battery. Even in cold weather, despite the fact that the capacity of most batteries can fall, a good generator allows you to ensure that the charge level is always above 60%. But now you need to figure out why the generator does not give charging and the battery sits down.

Basic Faults

In the event that the generator malfunctions begin to occur , it is necessary first of all to pay attention to the entire on-board network. It is possible that the wiring is broken, which records the excitation winding of the generator on the installation. Pay attention to the fact that the generator gives little charge in the event that its power is much lower than the total of all consumers. This happens when you installed on your car, for example, a very powerful speaker system, lighting, as well as other gadgets that are not provided in the standard configuration. This leads to the fact that when the internal combustion engine is running, the power of the entire on-board network is not only from the generator, but also from the battery. At the same time, the battery actively gives up its charge. But she does not recharge at this time. Therefore, when carrying out tuning of domestic cars, always pay attention to the generator set. It is desirable that there is a margin of power. Only in this case, you will ensure the most complete charging of the battery, as well as the ideal work of all consumers.

Breakdown algorithm

So, now more in detail about how to perform a search for all generator malfunctions. After all, the main reason is important to you. The generator does not give charging - it's just a symptom. In the event that the car's equipment is standard, you do not have unnecessary electrical energy users, you can easily start the diagnostics of the generator itself. In the same case, if you have additional consumers of electricity, they must be disconnected for a while. And you need to disconnect directly from the on-board network, and not just a button. First measure the flow recoil on the muffled engine. It is important for you to find out whether electricity is consumed while the car is parked. Please note that the alarm should be off at this time. Unfortunately, most domestic cars have a small leakage current. True, it is not capable of planting a battery even for a few weeks of parking. After that it is necessary to connect all consumers of electricity. Similarly check the leakage with connected consumers. In the event that the leakage current is very high, look for the cause of the failure not in the generator or battery, namely in any device connected to the vehicle's on-board network. This can be done by an exception method.

If there is no leakage current in standstill

It is much worse if there is no current leakage at the muffled engine, but the battery is discharged. For this, it is necessary to examine the generator more thoroughly. The reasons for the breakdown can be very high. Often there is no contact or it is very weak, in the brush assembly. In this case, of course, the generator does not give charging to the battery. This happens when the brushes are almost completely worn out. There may be a breakdown of the field winding. It is also possible that in this winding there is a shortage between turns. On the rotor, the winding can be closed to the housing. Similar malfunctions are sometimes present in the stator. It has three windings, which can also have breaks, a short to the case or between turns. In the event that the rectifier block contains one or more faulty semiconductor diodes, the generator will not output voltage at its output. And of course, a variety of mechanical effects can exert their influence. For example, stretching the drive belt. It is worth talking about all these breakdowns in more detail.

Insufficient contact

Please note that in the event that the brushes or the rings on the rotor are soiled or soiled, contact may be lost for a short time or permanently. It is possible that the brush holder spoiled springs. With their help, the brushes are pressed against the rings on the rotor. Consequently, the resistance of the common field winding is increased, or the electrical circuit is completely ruptured. In this case, the generator gives a weak charge or does not work at all. To get rid of this malfunction, sometimes you can simply wipe the brushes with a lint-free cloth. It is advisable to soak it in a solvent or gasoline. Of course, if the brushes are badly worn, they need to be replaced. In the event that the rings are oxidized, it is necessary to clean with a glass skins.

Destruction of windings

Not very pleasant, if suddenly there was a breakdown of the winding excitation. If there is such a malfunction, the generator will not work completely, since there is no magnetic field. The fact is that the basis of the principle of operation of any generator is the presence of a moving magnetic field. Determine this fault can be very simple. Firstly, if you touch the generator case during operation, it will be too hot. Secondly, a light bulb with a battery drawn on it will necessarily light up on the instrument panel. It signals that there is no charge on the battery. You can also use a multimeter in the resistance measurement mode. To do this, measure the resistance between the rings. But this is not all the reasons for which the generator does not give a good charge.

Closing between turns

Occurs in the event that the outer insulation of the wire wound around the winding is destroyed. Note that in the presence of interturn faults, the winding is excessively heated. In this case, the current consumed by the excitation winding increases manyfold. For accurate diagnosis, it is necessary to disassemble the generator completely, then measure the resistance of the coil with a multimeter. If it differs from the reference one, it can be concluded that there is a shortage between windings of the winding.

Shorting of windings to the body

In the event that there is a closure of the winding on the housing, the generator set ceases to operate. Most often there is a short circuit in the place where the terminals are located. These are the places where the winding is soldered to the contact rings. To check the rotor winding, you need to take a lamp with a working voltage of 220 volts. Please note that all safety precautions must be followed. You will need to connect one output from the lamp to the power supply. Connect the second terminal to the contact ring. The second power cable must be connected to the rotor housing. In the event that there is a closure of the rotor winding on the housing, the bulb will necessarily be lit. If there is no fault, the lamp will not light up. And if there is, then you could understand the reason why the generator does not give charging to the battery.

Problems in the stator

Similar problems can arise in stator windings. In particular, if there is an inter-turn short circuit, there will be no charging of the battery. Of course, the generator can work, but in emergency mode. First, its power will fall much. Secondly, charging of batteries will not occur. Thirdly, there is excessive heating of the generator housing. The winding can also be connected to the housing. Excessive heat, hum, reduced power - all those signs that are inherent in breakage of the rotor winding. The check is carried out in the same way as in the case of a rotor winding. To repair, replace all faulty coils. It even happens that in the generators the positive terminal closes with the case. Therefore, there is also a short circuit between the terminals of the battery. This is fraught with the possibility that a fire may occur. Of course, the generator does not give charging in this case.

How do I remove the generator?

You will need the following set of tools:

1. Mounting shovel.
2. Two keys for 17, one for 10 and 13.
3. Penetrating grease type WD-40.

The latter is extremely necessary in the event that the generator has not been removed for a long time, and there is a lot of rust and dirt on the thread. If this is the case, be sure to treat all joints with penetrating grease an hour before the beginning of the work. This will make it easier to carry out the work. At the same time pay attention to the condition of the belt, it should not be cut and otherwise damaged. If any, make sure to install a new one when assembling. It is possible that the generator does not give charging precisely because of a weak belt tension or its breakage.

Disconnect the "-" terminal from the battery, after which you can proceed with further work. Unscrew the nut that secures the "+" wire to the generator terminal 31. With the connection figured out, move on. With the key on 17, unscrew the nut from the upper mounting and push the generator aside towards the engine. At the same time, the belt tension becomes weaker and can be quickly removed. Then, unscrew the nut on the lower bracket, holding the bolt with the second key at 17.