Full generator check. How to check the generator for performance? Independent check and repair generator. Why the generator fails

The main source of electricity in the car is the generator. It starts simultaneously with the start of the engine, after which it produces energy and charges the battery. When it fails, the battery charge is not enough for a long operation of the car, so the driver is obliged to monitor the state of the generator.

Problems due to which the generator may fail during operation, weight. It can be both mechanical problems and electrical. The generator malfunction is also manifested by various symptoms, among which are the most common:

• The emergence of foreign sounds emanating from the generator;
• Battery Problems: Discharge, Recharge, Switching Electrolyte;
• Reduced brightness of headlight headlamps with increasing revolutions. This situation is considered normal if it occurs briefly when switching to the first transmission from the regime idle move on the "cold" engine;
• Signaling the control lamp on the discharge of the battery during the movement of the car;
• Failures in the operation of electronics, including the dim burning of headlights and a weak beep.

If the symptoms described above arise, it is necessary to check the car generator. Diagnostics, most often, is performed in four parameters:

• Verification of current flow rate;
• Diagnostics of the operation of the diode bridge;
• Checking the voltage regulator of the generator;
• Verification of excitation windings.

Depending on the identified problem in the diagnosis, the question of the feasibility of repairing the generator is solved.

Security rules when checking the generator

Before checking automobile generatorOne should familiarize themselves with the basic safety rules that will allow to preserve the health of the diagnosticity and not to deduce the aggregate. The basic rules for safe check and generator repair are as follows:

Please note: if not only the generator check is performed, but also welding with the body of the machine, you must begin to turn off the generator and the battery completely from the on-board network of the car.

Verification of the flow of the generator

For this generator verification, a multimeter is required, equipped with a special probe for measuring the current flowing in the wire. This probe looks like a clamp that covers the wire, and most often it supplies with a diagnostic device. To check the power of the generator gathering current:

1. Throw the clamp on the wire, which comes to the "B +" pin ("30") of the generator;
2. Next, start the engine and set high speed;
3. After that, one must include electrical consumption for car - radio, air conditioning, heating steering wheel and others. When you turn on each consumer, you should record the indications from the multimeter;
4. Next, you need to measure the strength of the recoil current when all consumers are turned on (which are included in the previous test).

When all measurements are obtained, you must compare the total indicator of the alternate inclusion of consumers and the indicator of the instantaneous inclusion of all consumers. It is considered invalid if the indicator when the instantaneous inclusion of all consumers per 5 or more ampere is less than the amount with alternately inclusion.

Checking the diode generator bridge

To check the state of the diode generator bridge, you must translate the multimeter to the alternating current measurement mode. Connect one measuring probe diagnostic device to the "B +" exit ("30"), and the second to the ground. Voltage with such a connection of probe should be no more than 0.5 volts. If the voltage is more, a short circuit of diodes occurred.

You can also check the diodes on the breakdown. To do this, the battery from the generator is turned off and the wire is also turned off, which is suitable for the "B +" terminal ("30"). Next, the multimeter is connected between the disconnected wire of the generator and "B +" ("30"), after which the readings are removed. If the discharge current multimeter shows more than 0.5 mA, the probability of a breakdown of diodes is large.

Checking the voltage regulator generator

To diagnose the status of the automotive generator regulator, you must use a voltmeter or multimeter in a voltmeter mode. Before the measurement starts, you need to start the motor, turn on the headlights and make the engine for 15-20 minutes. The measurement itself is carried out by the senses, which are connected between the mass and the output of the "B +" ("30") diagnosed automotive generator. The obtained values \u200b\u200bare recorded, after which they must be compared with normal numbers for a specific car model. Data numbers can be found in technical documentation cars. For most machines normal tension varies in the range from 14 to 16 volts. If there are deviations from the norms specified by the manufacturer of the car, the likelihood of the failure of the voltage regulator is large, in such a situation it will be necessary to replace it.

Verification of excitation windings

To check the good speed of the automotive generator excitation windings, the preload is necessary to remove the controller and the brush holder to access the contact rings. For diagnostics, an ommeter will be required, the probes of which should be applied to the generator contact rings. As a result of the inspection, the resistance must be at the level of 5-10 ohms. It is also necessary to make sure visually that there are no cliffs in the winding.

To diagnose the closure of the excitation winding "For Mass", it will be necessary to connect one intriguing omemera with any contact ring, and the second is applied to the generator stator. As a result of the measurement, endless resistance should be displayed on the screen.

When diagnosing the generator, it is also necessary to examine it for mechanical damage. According to the results of all inspections, the feasibility of repairing the device or its replacement is determined.

The generator is a kind of power plant, providing the energy of all engine systems: nutrition, cooling, ignition, so the output of its failure will inevitably entail other faults. To prevent breakdowns, it is necessary to systematically carry out its diagnostics, and if the problems failed to avoid immediately repair.

In this article we will talk about working capacity without resorting to the help of specialists. But first let's figure it out in the symptoms of its possible faults.

The main signs of the generator malfunction

The fact that the generator failed, or had problems in his work, the following signs will be prompt:

• permanent burning of the signal lamp in the form of a red battery on dashboard, indicating that or produces an insufficient current;
• constantly discharged battery;
• interruptions in the operation of electrical equipment (lighting and alarm systems, multimedia, heating and ventilation) with the engine running;
• appearance in the cabin ( motor compartment) characteristic burner odor;
• excessive heating of the generator stator;
• gul (rustling, whistling) generator.

The emergence of such signs is a serious reason to diagnose. To do this, it is not necessary to contact the maintenance station at all, as it is possible to check the generator on working capacity and on its own, especially if you have at least the slightest skills of handling the automotive tester. But first let's talk about the main breakdowns.

Main faults

The generator may have a malfunction of both mechanical and electric character. These include:

• failure failure;
• malfunction of the diode bridge (rectifier block);
• closing the rotor excitation winding;
• closure of stator windings;
• wear of brushes;
• bearing wear.

Check voltage regulator

The regulator is designed to stabilize the voltage produced before serving the car on the side chain, including the battery for its recharging. It is possible to determine its health independently can not otherwise check the charging of the generator, or rather, the voltage value supplied by it depending on the brand and the model of the machine it can be from 13.5 to 15.5 V. Therefore, before checking the operation of the generator for the subject Controller service, you need to find out exactly what kind of voltage it should issue. This information can be learned from the car manual.

How to check the generator multimeter? To do this, switch the device into a voltmeter mode and, observing the polarity, connect it to the coperators to the battery terminals when disabled Engine. A voltage is considered to be voltage within 12-12.8 V. Read the engine and repeat the procedure. The voltage on the terminals of the battery should grow to 13.5-15.5 V. only in this case, the regulator can be considered operational. Increase or decrease the amount of voltage, on the contrary, indicates that it is faulty.

How to check the diode bridge of the generator, without removing it from the car

It acts as a kind of rectifier, transforming an alternating current produced by the generator, permanent. Usually it consists of six, and three of them are "positive", three others are "negative", i.e., the first passes the current in one direction, the second - in the other. Checking the rectifier can be carried out both when the generator is removed and without dismantling it. Consider both options.

Before checking the diode bridge of the generator, without removing it, it is necessary to disconnect all the wires from it and from the voltage regulator, having previously turned off the "mass" terminal from the battery. To begin with, we will check the rectifier on include a multimeter in an ohmmeter mode, we attach a positive (red) probe to the output of the "30" generator (positive contact of the bridge), and negative to the generator housing. A working rectifier testing the device will strive for infinity. If the resistance is several Ohm, the rectifier is faulty.

Now let's talk about how to check the diode bridge of the generator for the presence of a breakdown. Let's start with positive diodes. Again we connect a positive probe to the appropriate bridge contact (output "30"), and negative to bolts (brackets) fastening the rectifier. The resistance should also strive for infinity. Otherwise, one or more diodes are pierced.

Go to "negative" semiconductors. The red tester probe is attaching to the rectifier fastening bolts, black to the generator body. The resistance seeking infinity is the right sign that diodes are integers.

Checking the rotor winding

A frequent malfunction of the automotive generator is the closure of the windings. This can happen as a result of a sharp voltage jump, water to wear, wear brushes, etc. So how to check the generator with a multimeter for the integrity of its windings, only having received full access to them, you will need to disassemble the entire node. We will not describe this process, since different cars It is different. Before checking the removed generator on the performance of the rotor winding, it is naturally necessary to disassemble.

After removing the rotor, we find contact rings on its shaft. There are only two of them. Turning on the multimeter in the module mode, connect it the probe to these rings. The device must issue resistance in the range of 2-5 Ohm. These are normal indicators for a good rotor. Higher resistance testifies to bad contact between rings. In the opposite when the instrument readings are approaching zero, most likely, there is an intercity closure.

How to check the generator for the performance of the stator windings

Go to Stator. It has several windings, each of which needs to be checked separately. But before this you need to disconnect the wires connecting the conclusions of the windings and the diode bridge.

Multimeter probe, included in the module, alternately connect to the outputs of each of the windings. The working winding has a resistance should be about 0.2 ohms.

Generator brushes wear

If the generator has been dismantled and disassembled, it will not hurt to check and the condition of the brushes. They may fail due to long-term operation, or as a result of problems caused by the rotor shaft disk. If brushes have traces of big wear, their geometric shape is broken, they are replaced.

Generator bearings wear

The car generator has two bearing. One of them is fixed on the Rotor shaft, the second is pressed in the central part of the cover. The hum, a whistling from the generator during the engine operation, is a faithful sign that some of the bearings ordered a long time to live. An accompanying symptom can be heating the generator body. Finding these signs, hurry to replace bearings. Otherwise, it will entail a rotor shaft breakdown or its encoffin with all the ensuing consequences.

You can check the bearings by removing the generator belt and checking its shaft. If the rotor rotates easily, without jerks and a backlash, the bearings will still serve. If rotation is difficult, or the shaft has a backlash, do not pull with the replacement of bearings.

In suspected of a violation of the generator's work, the owner of the car first seeks to identify the breakdown on their own. There are several ways to check, which suggest measurement both on the removed and at the notionable device. Check in both cases will be reliable. In addition to knowing how to check how to check the generator, it is necessary to find out the reasons for which it can fail. Although the generator is a fairly reliable device, but the wrong or negligent operation of the car can take it prematurely.

For what reason the generator may fail

Since the sign of a malfunction of the generator is almost always the same, then immediately identify the reasons for which he has failed without special equipment It is impossible. There are 4 main breakdowns, due to which the generator can lose performance.

1. Bearing jamming. During the operation of the machine in the generator, the constant movement of elements occurs, which leads to the disappearance of lubrication and further subdining or to complete the spare parts. Since bearings have large density, first of all, the belt is mainly rushed, which is responsible for their rotation. If the belt broke, then it is necessary to think about replacing either the generator bulkhead.
2. Rouge winding. The burned winding can occur for various reasons. The most common is the hitting of chemicals and salts that winter the road sprinkle. After the wiring burned or simply lost its integrity, current generation stops.
3. Wear or stitching brushes. The problems in the brush knot arise due to the fact that graphite rods were worn. This is enough frequent problemSince many motorists forget to replace brushes in a timely manner.
4. Breakdown relay regulator. This detail Warns Recharge rechargeable battery And the voltage in the specified parameters.

Since checking the generator on the car is not always convenient in the field, then it is worth spending in advance planned service And do not neglect the symptoms of the ambulance.

Features check

You need to know how to check the operation of the generator on the car correctly, otherwise you can encounter the fact that the service item will be fully disabled. Observing just a few simple rules, You can avoid unexpected breakdown.

1. Check should be carried out using a multimeter.
2. When diagnosing the valve condition, the current must have a voltage not higher than 12 V.
3. If you need to replace the wiring, you need to select the wires of the identical cross section with the source.
4. Before proceeding with the generator check, you need to make sure that all the attachments are connected and as a belt tension (read more about). If necessary, the connection is brought to a working state, and the belt pulls up either weakened.

The main condition in which the generator check is possible at home is the preservation of its working condition. If the device is disassembled or injured, which prevent it from functioning, then the diagnosis will not allow to find out the suitability of the device for further work.

There is a list of actions that categorically impose when checking:

• performance testing should not be performed using a short circuit or in other words "on the spark";
• connect terminals of different configurations with each other, as well as connect terminal 30 or B + to the mass;
• the diagnostics and operation of the generator should not begin without connecting consumers. It is especially important to comply with this item with a disconnected battery;

How to check the generator on working capacity at home

There are two basic test methods. One of them, though very old, but reliably makes it possible to understand the efficiency of the device. The second works more subtle and is able to respond to minor disadvantages of the system. Using the second method, you can identify the slightest deviations in the operation of each element.

How to check the generator by car without removing and having a necessary tool

There is an ancient way to identify the generator fault. It is very simple, but the result may consist of only two points:

• it works fine;
• there are malfunctions.

Since to check the car generator at home in this way anyone can, then its popularity is fully justified. You need to run the motor and turn on the Middle Light. From the working engine you need to remove the minus terminal. If the headlights are burning smoothly, and the engine tact did not hit, the generator works properly. With uncertainty dVS work Or change the brightness of the headlights must perform deeper diagnostics, since the device is in a faulty state.

How to check the generator multimeter

Measuring with special services will allow you to reveal even a little failure. There are a number of indicators that are considered optimal for all types of machines. The battery without load has a voltage within 12.5 - 12.7 V. Since when the motor starts, the load is superimposed on the battery, then the normal indicators are 13.8 - 14.8 V. after receiving the maximum load, the voltage indicator should decrease to 13. ,eight. If this does not happen or the voltage dropped even lower, then the generator checks.

Since all car enthusiasts can correctly ring correctly, then when identifying a malfunction, but if there is no possibility to diagnose yourself, it is better to contact the service center. Experienced masters will be able to suggest the causes of breakage and will be explained why it did not work out.

Check voltage regulator

The sequence of actions is as follows.

1. To check the status of the voltage regulator, you will need to use a voltmeter, the scale of which should be from 0 to 15 V. Diagnostics must be performed only on a well-haired motor. For this, the car starts 15 minutes and headlights turn on.
2. Measurement is carried out between the output of the mass and 30 terminals. For most cars, the norm is very easy to find, since it has a majority in the range of 13.5 - 14.6 V. The numbers below 13, they say that the details are necessary for urgent replacement.

This method is one of the methods of checking the generator without a car. For diagnostics, access to the battery and the device itself will be accessed. The voltmeter is used in the measurement mode and connects to the mass and climb in + on the battery. After switching on the special equipment in its window, the indicator should not exceed 0.5 mA. If the indicator is higher, this indicates that the diodes have failed either impaired integrity of insulation on windings.

Verification current return

This check is performed only with the motor connected. This method is quite problematic and requires a large amount of time and scrupulusity. The essence of the diagnosis is to measure the current consuming electricity. The engine must start and achieve the highest speed. The probe is installed on the wire, which goes to the climb 30 or B +.

Alternately, you need to include all the electrical appliances of the car, and the indicators from the multimeter to write. After the results were obtained, the numbers need to be folded. Next, all electrical appliances should be included and compare the indicators on the measuring equipment with the amount of past studies. It is considered the norm indicator of 5 A less from the amount received, but the increased evidence of spare parts fault.

Checking the generator excitation current

The engine should work in mode with the highest speed. The multimeter is connected to the terminal 67. The device will immediately show the result and the magnitude of the excitation current. In a working generator, this indicator is within 3 - 7 A.

Verification of windings

Check the condition of the winding can not only be visually, but also with the help of special devices. This manipulation involves conducting preparatory work:

• dismantling the brush holder;
• removing the voltage regulator;
• cleaning contact rings;
• check on the lack of defects in the winding.

The generator is the main source of current supplying the electrical appliances of the car. The automotive generator malfunction entails insufficient charging of the battery, which leads to a drop in voltage, de-energizing and complete electrical appliance stops. For this reason, it is necessary to regularly check the health of the generator and immediately respond to malfunctions in its work.

Signs of mechanical damage generator

The presence of extraneous noise may also be a consequence of the intersperious closure of the stator winding. Similarly, the fault of connections and contacts is manifested, closing the winding on the housing. All this talks about the problems of interaction of parts when the generator is working. Can be identified by visual inspection mechanisms. It is easy to detect unwanted winding closures, bad contacts and connections. Depending on the detention of identified faults, it is possible to make a decision on the possibility of eliminating them independently or by contacting the specialists.

Car generator voltage diagnostics

However, it is most often enough to use a voltmeter. It must be connected to the terminals of various battery panels and start the car engine.

After troubleshooting, a serviceable generator is mounted in order to dismantle it. The final action of this process should be cautiously connecting the mass.

After installing the generator, you should again check the voltage indicators on the battery poles. When the engine is running for 3000 revolutions per minute, they should vary from 13.5 to 14.5 volts. These values \u200b\u200bmean that the operation of the generator is restored, and it is working.

Check voltage regulator

The next stage of diagnostics will be the voltage stabilization check. To do this, turn on automotive headlights of long-range lighting and using a voltmeter to measure the voltage on the battery poles. Deviation of values \u200b\u200bnot exceeding 0.4 volts from previous measurements when the engine is started, indicate the operation of the generator. Deviations in the most part indicate unstable work Generator, the search for the causes of its malfunction will have to continue.

Car power supply chains check

Further search for the causes of the generator performance loss is to diagnose the chains of the car's power supply. For this purpose also need a measuring appliance. With it, first it is necessary to check the diode bridge. The voltmeter in this case is connected to the generator and mass terminals. The values \u200b\u200bof the device exceeding 0.5 volts mean malfunction of diodes. To determine their breakdown, the measuring device should be connected between the "30" output and the generator connecting wire disconnected. Acceptable with the power of electric flow less than 5 mA.

Then the voltage regulator is checked. The engine should warm up about a quarter of an hour on medium turnover. In this case, all car lighting devices must be turned on. The field of this is measured by mass and withdraw "30". The optimal indicators of the device may differ in this case depending on the type and brand of the car, which can be found from its technical characteristics.

Also, the indicators of the adjustable voltage depend on the vehicle modification and its parameters, which can be measured when connecting the tester to the battery. This measurement is performed on the maximum turnover of the engine operation with all inclusive electrical appliances of the car.

Multimeter is needed when diagnosing a mass closure. To do this, put the tester into the "transk" mode, one dipstream touch the anchor hull, in the second - contact ring. Everything is simple: it does not ring - fodder, rings - faulty.

Conclusion

Guided by these recommendations, the diagnosis of the automotive generator can be performed independently. To do this, you will need only certain skills of owning the simplest tools when dismantling and mounted, as well as the use of electrical meters. However, for more accurate checks and thorough diagnosis, you should contact certified car services, qualified specialists whose specialists will quickly identify and eliminate all malfunctions in the generator.

Video: How to check the generator

The car generator is the main source of energy in the on-board network and when it or fails, you will not drive for a long time on the same battery. That is why it is so important to control the operation of the generator.

The full range of generator checks includes:

In most cases, it is not difficult to check the car generator with your own hands, because on what kind of car you did not check, the principle is the same. But still, many car owners are often wondering: how to check the generator by a multimeter or undergraduate means?

How to check the generator without removing the car

There are two ways using a multimeter and without it. The first, relatively new, is that, and the second, old and verified, almost in the opposite - the battery terminal must be removed on the engine running.

1. Verification of the battery multimeter First takes place at rest - the voltage must be within 12.5-12.8 V. Then it is necessary to measure the readings already on the engine running, if 13.5-14.5 is observed at 2 thousand turns, it means everything is in order. With that on new cars even 14.8 in quite normal, as manufacturers assure - the abundance of electronics affects. In conclusion remains check voltage under load, that is, connecting consumers - stove, headlights, heated, radio. Failing within 13.7-14.0 V is considered to be permissible, but 12.8-13 in already talk about a malfunction.
2. The second way, like many "grandfathers", simple and trouble-free, but at the same time rather dangerous and requiring accuracy. According to statements, it works both on vases and on relatively new cars, like Aveo. What is the essence - weaken the bolt of fastening the minus terminal of the AKB key to 10, start the engine and give a small load by turning on one of the consumers, such as headlights. Then remove the terminal when the motor running is if it does not stares and the headlights are not a meal, it means that everything is fine with the generator, otherwise you can be sure that it is broken. Trying such a method should be at your own risk.

It is extremely unwittingly to allow the operation of the generator with the disconnected consumers, especially the battery. This can lead to a relay controller malfunction.

Finding out that there is a malfunction, you should dismantle and check the removed generator with a multimeter, a light bulb and visually. The check is subject to each of its elements separately.

First of all, it is worth making sure that the generator belt is well stretched, and the bearings are not broken. Foreign noises and a very hot generator talk about wear of bearings.

How to check brushes and contact rings

For the start of the ring and the brushes visually inspect, and their condition is estimated. For example, the minimum residue is measured (min. the height of the current-piece brushes do not 4.5 mm, and min. Rings diameter 12.8 mm). In addition, they look at the presence of workings and furrows.

Brushes extracted from the brush knot of the regulator

Generator Rotor Contact Rings

How to check the diode bridge (rectifier)

Checking the diodes is made by measuring resistance and detection of conductivity. Since the diode bridge consists of two plates, then check one immediately and then another. The tester should show the conductivity of diodes is only in one direction. Now a little more details: one tester probe is kept on the "+" terminal, and then alternately check the conclusions of the diodes, and then change the probe (in one case there should be great resistance, and there is no other). Then we act in the same way and with another part of the bridge.

It should be noted that the resistance should not be zero, as it says that the diode is punched. The punched diode of the bridge and then when there is no resistance in both sides.

Checking a diode bridge

Checking contact rings

At least one the unsuitable diode leads to the failure of the entire diode bridge And gives an abbance of the battery.