Malfunction of the generator. Generator circuit

Let's figure out what is needed and how to repair the car generator. Faults in the device occur for a variety of reasons. In addition, if this happened on the road, then a breakdown of this kind causes a lot of trouble. The fact is that all the load goes to the battery, therefore, it discharges quickly enough.

Generator circuit and principle of operation

If you do not go deep into the details, the device works quite simply. Due to the copper winding, a rotating magnetic field is created on the rotor. At the same time, there is a pulley on the rotor shaft, as well as a fan impeller. When the key is turned in the ignition lock , a current flows into the copper winding that is located on the rotor, resulting in a magnetic field on the winding. Consequently, the rotor is driven along with the crankshaft of the engine. When certain revolutions are reached, the winding is fed not from the battery, but directly from the generator, that is, from the excitation mode to self-excitation.

Since we receive an alternating voltage, a rectifying unit is installed, which converts it to a constant one. It is worth noting that the circuit of the generator is quite simple, so anyone can take it out with it. During the movement from the generator receives an electric current and a rechargeable battery. Tracking the efficiency of the generator can be done using a special sensor on the car's instrument panel.

How to understand that the electric current generator is defective?

There are a huge number of ways to find out whether the device works normally or not. The simplest of them is to look at the battery charge level of the engine that is running. If the arrow tends upwards (to full charge), then the generator works, but if it is in the red zone, then it means that all electrical systems of the car are powered directly from the battery, which is not good.

Also, a generator malfunction may not exist, in fact, in cases where the sensor itself is defective. The same applies to the lamp on the dashboard, which can fail. A prerequisite for breakage may be increased noise, whistling during the operation of the engine, as well as much more. In most cases, due to insufficient maintenance of this unit.

Since the device is located in the front of the engine, it's easy to get to it. Therefore, it should not be difficult to periodically lubricate rubbing surfaces, tighten / loosen the belt on pulleys, and, if necessary, replace it.

Independent diagnostics of the generator

If you do not want to go to the car service, then you can check the device yourself. As an example, let's take the so-called "classic" VAZ-2107 with a typical generator. The first thing to do is start the engine, then watch the lights. If it is stable for several minutes, then there are no faults in the VAZ-2107 generator. If it is dull, it is most likely the fault of the weakening of the pulley nut or the insufficient or excessive tension of the belt. If you apply an effort to the belt equal to 10 kilograms / force (kgf), then the total deflection should be no more than 10-15 millimeters.

If the received value was more or less, then it is necessary to tighten or, accordingly, loosen the tension. Also, the fault can be determined by the incomprehensible noise in the engine compartment. This happens due to the fact that the vibration of the pulley nut is loosened from vibration, so that it starts to work more noisily and less efficiently. And now more in detail about the basic malfunctions.

Control devices do not work

As it was noted at the very beginning of the article, when turning the key in the ignition switch, the control lamp of the generator should light up. If this does not happen, then we need to look for a problem. Do not immediately climb under the hood and dismantle the device, because often this is not a malfunction generator, and the problem is solved much easier. It is necessary to check the fuse in the mounting block under the 19th number, if it is blown, then replace it, and the control devices will work.

Another problem is a break in the circuit, because of which the voltage from the ignition switch to the assembly unit or from the unit to the instrument panel may not be applied. All this is easily eliminated. The first step is to check the wire "0", and then "TP". One is responsible for supplying current from the unit to the panel, the second from the ignition lock to the unit.

The test lamp does not light, the battery is discharged

Of course, the instrument panel uses an indicator that can simply burn out, and you do not need to look for something more in it. Sometimes it's just enough to replace the lamp. There are also malfunctions of the generator of the car in the form of insufficient pressure of a cartridge of a lamp to a printed circuit board, owing to what and there are malfunctions on the instrument panel.

As we know, all sooner or later goes out of order, even with the most careful care. This applies to the generator. Brushes of the device quite quickly wear out, resulting in problems with work. In this case, they simply need to be changed. Exactly the same situation with the oxidative processes of metal, which no one has yet canceled.

The contact rings are oxidized, therefore they fail. To eliminate the problem, you must first change the brush holder, and then carefully wipe the rag or napkin with oxidized rings, for greater effect use gasoline or acetone. Worst of all, if the positive diodes are closed, because in this case it is necessary to completely change the mounting block.

Malfunction of the generator: battery discharge, unstable burning lamp

Almost every driver has experienced by his own example an annoying whistle from under the hood. It's all the fault of the generator belt, which slips due to wear or insufficient tension. If you are faced with such a problem, then the usual adjustment or replacement of the belt is enough, its cost is small, on the order of 100-200 rubles.

It is impossible not to say that the main generator faults are the damages of the rectifier block diodes and the rotor winding. As in the first, and in the second case, this entails not the best consequences. The problem is eliminated by replacing the rectifier unit or, if possible, the diodes.

There are also closures in the stator. In most cases, this damage is not subject to repair, and if restoration work is possible, the new stator is much cheaper and easier to buy. There may be a short circuit to the so-called "mass", in this case it is necessary to change the part.

Increase noise threshold, recharge battery

First, let's talk about why the generator starts to work noisily. The fact is that during operation the bearings work out their life, which is measured in hours. Consequently, after a certain number of hours they fail. These places start to work unstably, there is backlash, knocking, etc. Consequently, the noise level increases.

Of course, it is extremely difficult to foresee such causes of generator failure, however, one must be able to understand that the bearing has failed and it is time to change it. When the so-called "howl" of the generator appears, this indicates, at least, the presence of an inter-turn closure in the stator. It is fraught with consequences and easing of a nut of a pulley of the generator, it needs to be tightened tightly.

A little more about malfunctions

There are also such generator malfunctions as recharging the battery, this can be traced by the arrow of the voltmeter on the instrument panel. The reason for this can be an exceptionally faulty voltage regulator, which can not cope with its direct purpose. It can be repaired or replaced.

Everywhere there is a weak point, this also applies to our case. This generator malfunction, like wire oxidation, occurs more than often. Fortunately, with you it's enough to have a sandpaper or a brush for metal, which removes oxide. By the way, the presence of oxidizing processes can cause a complete failure of the generator, which is due to the deterioration of contacts.

Do not forget that the bearings need lubrication, this will increase their service life. When the axle play appears on the armature shaft, it only says that it's time to change the bearing. Do not give preference to unknown producers. It is better to buy a bearing of a well-known company, let it be more expensive, but its resource is an order of magnitude larger. In general, there is a special stand on which you can determine the general state of the device. There is a diagram of the generator, breaks in the chains and much more.

Important points

We can not say that periodic testing of the device's operation is a guarantee of trouble-free operation. Of course, no one is immune from short circuit, but to check the belt tension, the condition of the brushes and rings can and even is necessary.

Under no circumstances need to work with the generator when the engine is running, as this is dangerous for health, because we are dealing with high crankshaft and fan speed. As it was mentioned above, the generator circuit is very simple, so if necessary, it will not be difficult to study it. This will allow not only to understand how the device works, but also to perform most of the repair work on its own.

Conclusion

If we are dealing with "classics", then there are often enough problems with wires. They must be re-soldered and cleaned. The same applies to the generator belt, which, due to intense wear, can tear. By the way, its break during the movement of the car is fraught with the fact that there will be a strong blow. As a rule, the hood gets most of all, there are cases when, due to a strong blow, the paint flaps from the front side of the hood.

It would be superfluous to carry a spare belt. This will eliminate some of the malfunctions of the VAZ-2107 generator directly on the road. Also, you need to have the necessary tools, that is, a flat and cross screwdriver, a set of keys, etc. Here, perhaps, and all that can be said about what are the signs of a generator malfunction and how to eliminate them.