The alternator is the vehicle's main source of electrical energy when the engine is running. Malfunctions in the operation of the generator entail extremely negative consequences. For this reason, the performance of the generator should be carefully monitored. On most cars, checking the performance of the generator with your own hands will not be too difficult. Checking the car's alternator is carried out using a multimeter and is carried out according to the same principle on all vehicles.
The main elements of a car generator are:
- Stator with windings;
- Rotor;
- Diode bridge;
- Voltage regulator;
- Pulley;
- Covers made of aluminum alloys;
- Fan;
- contact rings;
- Voltage rectifier;
- Bearings;
- Nuts, bolts and washers.
The main purpose of a car generator is to convert the mechanical energy coming from the engine through a belt drive into electrical energy. The electrical energy converted by the generator ensures the normal operation of the vehicle's on-board electrical system and battery charging.
Signs of a malfunctioning generator
According to statistics, malfunctions in the electrical system of a car are in the top three in terms of frequency of occurrence. By type, they can be divided into two main groups, the first is power consumers (headlights, ignition, radio, on-board computer, etc.), and the second is sources of electrical energy (battery and generator).
Faults occurring in the generator can also be divided into two main categories, namely:
- Mechanical failures;
- Electrical faults.
This separation occurs due to the fact that the generator is both a mechanical unit and an electric one.
The mechanical type of malfunctions of the car generator include:
- Deformation or damage to the body and fasteners;
- belt wear;
- Malfunction of bearings;
- Compression spring failure;
- Other malfunctions are not related to the electrical part.
The electrical type of malfunctions of the car generator include:
- Wear and burnout of graphite brushes;
- Insulation breakdowns;
- Breakage of the stator windings;
- Interturn short circuit of the stator windings;
- Faulty diode bridge;
- Closures.
The main signs of a malfunctioning car generator:
- Extraneous sound emitted by the generator;
- The battery is being recharged or completely discharged;
- The control lamp of the storage battery discharge is constantly lit when the engine is running;
- Weak glow of the headlights of the vehicle when the engine is running;
- Weak sound signal when the engine is running.
Interesting! Some symptoms may occur on certain types of engine, as a gasoline engine will not be able to run for a long time with a faulty generator. This is due to the fact that the battery is discharged and the spark on the spark plugs ceases to be produced. This problem is not characteristic of diesel engines, since the ignition of the fuel mixture in the cylinders occurs due to compression. And in the daytime, it is not always possible to notice a breakdown of the generator.
Safety precautions at work, what not to do when checking the generator
During work related to the repair, replacement and troubleshooting of a car generator, in no case should the following be allowed:
- Hit of antifreeze, oil or other liquids directly on the generator;
- If the voltage rectifier (diode bridge) is faulty, leave the car with the battery connected;
- With the terminals removed from the battery, leave the generator on;
- Close the outputs of the generators to each other to check its operation;
- Disconnect the battery terminals with the engine running.
How to test the voltage regulator
Not a single car generator is able to do without a voltage regulator. This element of the generator provides support for DC current. So if the voltage regulator malfunctions, the current strength of the electricity generated by the generator will constantly change, depending on the engine speed. So at high engine speeds, the voltage will reach more than 20 volts. As a result, this voltage will disable all consumers of the vehicle's electrical system.
Important! To check the operation of the voltage regulator, it is necessary to involve an assistant.
Checking the performance of the voltage regulator occurs on a running engine using a multimeter, and is performed in the following sequence:
- Open the hood of the car;
- We prepare the multimeter (we set it to the “measuring direct current” position);
- The assistant gets into the car and brings the engine up to 3 thousand rpm;
- We measure the voltage at the battery terminals (if the voltage at the terminals is normal and does not exceed 14.8 volts, the voltage regulator is considered to be fully operational, otherwise we proceed to the next step);
- Using an additional (preferably copper) cable, we connect the car body to the generator body;
- We bring the engine to 3 thousand rpm;
- Once again, we measure the voltage at the battery terminals (if the voltage is again above normal, this indicates a malfunction of the voltage regulator);
- If during the second check the voltage is normal, this indicates a poor ground contact. To eliminate this problem, it is necessary to clean the contact surface of the "mass".
Important! A voltage of 14.8 volts is considered the norm in passenger cars, with electrical consumers turned off (lights, radio, air conditioning, etc.).
How to check the diode bridge of the generator
The diode bridge of the car generator acts as a voltage rectifier, it provides the conversion of alternating current to direct current. Its feature is that it allows the passage of electric current through itself in only one direction.
Checking the diode bridge of the generator is carried out using a multimeter and is performed as follows:
- We set the multimeter to the "dialing" mode;
- We call the diode;
- We change the probes in places.
- We call this diode again;
- We repeat this procedure with all diodes.
Important! Serviceable diodes should ring in only one direction and have a resistance of 450-800 ohms.
Recoil current, how to check the recoil current
The recoil current is checked using multimeter clamps. The process of changing the recoil current is most conveniently carried out with a partner.
Checking the output current of the car generator is as follows:
- The partner starts the engine, and brings its speed to 3 thousand;
- With the pliers of the multimeter, we grab the wire going to contact No. 30 (B +);
- We turn on all the electrical consumers in the car in turn (we write down the indicators of each electrical consumer and add them up);
- Now we turn on all the electrical consumers at the same time, and record the readings of the multimeter;
- We compare the readings of the multimeter, the differences between the two readings should not exceed 5 amperes.
Generator excitation current, how to check generator excitation current
The excitation current of the generator is also most conveniently measured with a multimeter tongs. It is most convenient to make measurements with a partner. The generator excitation current is measured as follows:
- The partner starts the engine, and brings its speed to 3 thousand (the engine should run at high speed for a short time);
- Set the multimeter to ammeter mode;
- With the pliers of the multimeter, we grab the wire going to contact No. 67 (D +);
- We take readings from the multimeter;
- The excitation current on a properly functioning generator should be between 3 and 7 amperes.
To avoid problems with the operation of the generator. It is necessary to periodically check the tension of the vehicle alternator belt.
When performing welding work on the car body, it is necessary to disconnect the terminals of the generator and battery from the car.
Take immediate action when the battery indicator lights up.
It is necessary to periodically clean and tighten the electrical wiring contacts. This will greatly increase the life of the vehicle's electrical system.
Checking the operation of the car's generator is best done together with a partner. This will greatly facilitate and speed up the process of checking the operation of the generator.
A car generator can fail for the following reasons:
- wear of the rotor bushings of the excitation coil;
- voltage regulator malfunction;
- breakdown of rectifier bridge diodes;
- short circuit or open windings;
- collector zone failure.
Most of these faults can be diagnosed without removing the alternator from the machine, since this work in some vehicles requires special tools, access from the bottom, complex plumbing operations.
Excitation coil rotor bushing wear diagnostics
Wear of the rotor (armature) bushings of the excitation coil leads to an increase in sliding friction, and as a result, overheating of the generator, a decrease in the efficiency of converting mechanical energy into electrical energy, and an increase in the load on the car engine.
Video - how to check the battery charge from the generator:
In the most critical case, the bushing may break and the rotor may jam. This can cause the alternator belt to break, which in turn can lead to serious engine problems.
That is why the timely prevention of the generator begins with the bushings. Sometimes bearings are used instead, although bushings are more reliable.
The wear of the bushings is usually diagnosed by a characteristic metallic ringing during the operation of the generator, an increase in the stretching of the generator belt.
It is easier to remove the belt and check the beating of the alternator pulley by hand, moving it perpendicular to the axis. The presence of even a small backlash indicates the need to replace the bushings or bearings.
Voltage regulator failure
The voltage regulator provides a constant voltage level at the generator outputs at various engine speeds. If you look at a typical generator circuit, the voltage regulator controls the current of the field coil.
The generator is a self-regulating system. If the speed increases, the voltage on the regulator increases, it reduces the current flowing through the field coil. According to the law of induction, the voltage on the stator coils decreases, and therefore the voltage at the generator output.
Video - how to check the generator on the car without removing it:
During normal operation, the generator provides, with the engine running, a stable voltage on the battery in the range from 13.3 to 14.5 Volts, regardless of engine speed.
Exceeding, as well as a lower voltage level, indicates a possible malfunction of the regulator, it must be checked.
Structurally, the regulator can be made in the form of a block with or without brushes.
It is sometimes referred to as a "pill" or "chocolate".
In most cases, it is easy to dismantle it without removing the generator and check it at home or in a garage. A typical voltage regulator test circuit is shown in the figure.
As a lamp 6, you can use any salon light bulb. 1 - battery, 2 - relay-regulator, 3 - electronic unit, 5 - terminal for connecting a thin wire going to the generator. If the lamp is lit, then the regulator is working. But if at the same time the battery charge voltage is more than 15 volts, the voltage regulator still needs to be changed.
Video - checking the generator on a car with a multimeter:
It is also necessary to change the regulator if the brushes are badly worn. However, if you have some experience repairing power tools, you can try to change the worn brush (preferably both brushes at once).
In almost half of the cases, a generator malfunction is due to a failure of the voltage regulator.
Breakdown of rectifier bridge diodes
Perhaps this is the most dangerous and difficult to fix malfunction. Very often it occurs when the battery is reversed. This is when the battery terminals are connected in reverse polarity. In this case, several more fuses and blocks of the car may burn out.
Video - checking the generator at home:
Typically, diodes fail in pairs, since the breakdown of one causes a forward voltage to be applied to the series diode. When a diode breaks through, its resistance becomes almost zero.
In this case, the generator starts to overheat, the load on the battery increases. A breakdown of the diode bridge can cause a short circuit in the wiring, fire.
If there is a burning smell from the generator area, the generator is overheating, immediately disconnect all wires leading to the generator, especially the thick wire. Carefully isolate them and follow to the parking lot.
Video - how to check a diode bridge on a car generator:
Checking the breakdown of the rectifier bridge diodes is simple. The generator should "ring out" like a diode. To do this, switch the multimeter to the "Diode" position. Then disconnect all terminals from the generator. First, connect the multimeter probes between the thick wire terminal and the vehicle ground in one direction, then in the opposite direction. In one direction it should “ring” (resistance from 200 to 1000 Ohms, like diodes in direct connection), not in the opposite direction (the resistance is very large, more than a hundred kiloOhms).
Of course, it is better to remove the generator, disassemble it, dismantle the diode bridge and ring each diode individually.
Sometimes diode bridges of generators are called "horseshoe", it is clear why. Round ones (6 pieces) are power diodes, they usually burn out, it is difficult to change them. When installing them, soldering is not used, but welding. At worst, a faulty pair of them can simply be bitten out without changing. The generator will still work, although not at full capacity. Cylindrical diodes serve the voltage regulator. They fail less often, but it is also necessary to check, as described above.
Short circuit or broken windings
If a winding break can still be somehow detected with a multimeter, and then by disassembling the generator, then the short circuit is poorly diagnosed, since the resistance of the windings is low.
Video - how to check if the generator is working on the machine without removing it:
The main symptom of a malfunction of the generator windings is a change in the color of the varnish insulation of the copper conductors of the generator winding. With increased short-circuit currents, the color of the wires becomes much darker. This is accompanied by a burning smell during the operation of the generator.
You can give the generator for rewinding, but it is now expensive. If it is possible to buy a similar or matching fit from another car, it is better not to rewind.
The color change of the windings can be detected visually. The generator has many technological holes for cooling; in good light, you can examine the color of the windings.
Collector zone fault
Collector - these are brass cylindrical contacts of the exciting winding, along which the brushes move.
They usually wear unevenly. This leads to sparking in the brush area, overheating of the commutator, and even greater wear of the brushes and commutator.
During the maintenance of generators, the collectors are bored and ground. This cannot be done indefinitely, therefore, after several repairs, the collectors are changed.
Video - a quick check of the generator without installing it on a car:
You can diagnose the deterioration of the collector with the generator disassembled. If you remove the voltage regulator with brushes, you can feel the collector area with your finger. If she is "humpbacked", you should think about prevention.
It is possible to detect the sparking of the brushes with the engine running, and this is evidence of the wear of the collector, at night by turning off all the lighting devices.
The generator is one of the most conservative parts of a car. Its design has remained virtually unchanged for more than fifty years. If routine maintenance is carried out in time (cleaning, replacement of bearings or bushings, belt, brushes), it will last a long time.
Video - how to ring the generator with a multimeter:
May be of interest:
Scanner for self-diagnosis of a car
How to quickly get rid of scratches on the body of a car
How to check a used car before buying
How to apply for an OSAGO policy online in 7 minutes
Similar articles
Comments on the article:
Alexander
I usually check the generator in the fall, before the cold weather. It takes a little time, but it saves you from additional expenses for buying a new one or repairing it. Lubricate in time, wipe the collector in time. As practice shows, it is true that most often either the regulator or the diode bridge fails, but in this case not everyone can cope with such a problem on their own.
Valentine
The rectifier bridge, consisting of diodes and a regulator, heats up quite a lot during operation, and its cooling is very weak, due to design features (located at the rear of the generator).
When driving into a deep puddle, immediately the flow of water from under the wheel causes a sharp cooling of the diodes, in my practice this is the reason for their failure in 80% of cases.
Oleg
The failure of the bridge diodes can be detected by undercharging the battery. On my Chevrolet Niva, due to the failure of the reverse diode, the lamp on the panel was constantly glowing dimly. When I disassembled the generator, I simply rang all the diodes with a multimeter - one was broken. I bought a diode in a radio tent (there are no Russian ones, only an imported analogue) I soldered and assembled the generator. All work for 12 rubles. and work hours. The service was first offered to change the generator — work + generator about 5000 rubles.
Sergey
I have a special relationship with the generator: on two of my machines the problem was the same. At first, the battery began to undercharge in one car (there was no charge indicator lamp on the panel), in the other, the recharge lamp began to glow dimly. Both cars followed the same path: first, I measured the battery charge voltage at the terminals. Then I changed the “pills”, and only lastly dismantled the battery. In both cases, a broken diode in a horseshoe. In the first case, I did not find a diode (it was in times of shortage), so I replaced the horseshoe. I remember it cost about 200 rubles. In the second case, I found an imported analogue in the reference book. I bought (15 rubles), soldered the diode and all the problems were gone. But in no case, as the author of the article writes, was the second diode affected. By the way, the service offered to replace the generators and nothing more.
Lyokha
I agree that it is not necessary to be an ace of radio engineering in order to carry out the simplest measurements with a tester. I try once again not to go into the auto electrician, there are specialists for this, but sometimes the need forces me. From personal experience, I came to the conclusion that serious breakdowns are rare. Usually, either the wear of the brushes, or a break (burnout, poor contact) of the wiring. I sincerely advise - do not rush to buy a new generator, in 49 cases out of 50 repairs cost a penny (or even free of charge).
Vasya
I doubt that it is generally worth checking it with a tester. For the average motorist, he is only interested in whether the generator is working or not. To do this, it is enough just to reset one of the terminals from the battery with the engine running. If the engine does not stall, then the generator is running. This method is actually harmful to both the electronics and the generator. But nevertheless the most effective 🙂
Kolya
Here I read that it is advised to check by disconnecting the terminal on the battery. So you can't do that! If such a focus channel on domestic cars (Zhiguli, Volga, Muscovites) where, in principle, everything is oak and analog, then on a serious foreign car you can easily get to buy a generator or even worse, a control unit. And I think it still makes sense to measure the voltage on a running motor with a tester. If it starts to deviate from the standard 14.4 Volts, then this can indirectly indicate wear on the generator brush assembly. And in this case, it is better to overdo it than to be left without charging in the middle of the road.
Sergey
The alternator may be OK, but the indicator light may be flashing, which may indicate a wiring problem outside the alternator. Therefore, in self-checking, not everything is so simple. It is better to carry out a complete diagnosis of electricians at a service station, where they can determine in advance an unforeseen breakdown and percentage of wear. But there are advantages to self-testing - you get certain knowledge and skills.
Dmitriy
The generator is almost an ordinary electric motor, if you twist it and connect a light bulb, it will start to glow - this is an elementary generator.
Its main malfunctions are: stuck bearings, one of the common problems for generators that have been in operation for a long time; the winding of either the stator or the rotor burned out, this is most often from a high speed of travel through water; failure of the brush assembly; failure of the relay regulator.
If the alternator stops working, this can already be seen in the cabin - the battery emblem on the instrument panel will light up. It is necessary to react immediately otherwise you can discharge the battery. The second signal is a dim glow of all devices, which means that the car is running on battery power, and not on a generator.
There are two ways to do this check. First multimeter. We measure the voltage at the terminals on the idle engine - it should be 12.5 - 12.7 V. We start the engine - it should be 13.8 - 14.5, although some manufacturers say that 14.8. Then turn on the load - the voltage should not fall below 13.7 V. If it is lower, 12.8 - 13V, then the generator is not working, you need to check it.
The second way is the old grandfather method. Do it very carefully! We turn on the engine, turn on the load and remove the minus from the battery. If the machine continues to work, the generator is working, it has stalled - the generator has died. So I checked on the VAZ 2108, Mazda, Opel, Chevy Niva.
Irina
Worked at the service station. The generators themselves were not made, they were taken to a special repair of generators. And you're talking about yourself!
Danila
Well, in the beginning I want to answer the last commentators Dmitry and Irina. The method of checking by disconnecting the battery is fraught with failure of the brains of the car, it was on old machines that there was no electronics, except for the switch at the VAZ 2108 and there was nothing to burn. The battery is a rather large load on the generator, and when it is disconnected, a sharp increase in voltage is possible, which is fraught. Now Irina - your “specialists” didn’t do it themselves just because they didn’t want to waste time, and any driver who is versed in technology can fix the generator (with the exception of rewinding it). Now to check. I only check with a multimeter, if the voltage on the battery with the engine off is 12.4-12.6, then with the generator running it should be 13.5-14.5.
Igor
The generator is the most important part of the car, your ability to drive a car, battery discharge depends on its failure. In order to prevent this from happening, you need to monitor the state of the generator.
However, there are mandatory rules, the observance of which will not damage the generator. This includes: checking the generator for a spark, i.e. for a short circuit, here we also include the connection of terminal “30” with ground; operation of the generator with the battery disconnected; any welding work on the machine with the generator on; checking generator diodes (horseshoes) with a voltage of more than 12 V.
To check the generator, I personally use a multimeter with a Krona battery, it is 9 volts. Most often, the voltage regulator fails and in order to check it, first I warm up the engine for 10-15 minutes. Then, in the position of a voltmeter with a scale of up to 20 V, I measure the voltage between the generator ground and the “30” stamp. The voltage should be in the range of 13.5-14.5 V. If it is lower or more, then the regulator may have failed, I have a spare one and I use it for testing.
In addition, you can check the voltage on the battery, it should be higher than 12.6 V.
For those who understand the electrics of a car, there is also a check of the diode bridge, the recoil current and the excitation current of the generator.
Anton
On my car "Seven Zhiguli" I repeatedly had to repair or replace the generator. This is one of the tightest spots on my car. There are two main failure problems. The first is the failure of the bearing of the tension belt pulley of the generator drive; the second is a breakdown of the rectifier bridge of the generator. According to the first breakdown, the diagnosis is simple, the noise of the bearing is heard far from the car, but the second reason can be established only by removing the generator. If there is a device, you can also do diagnostics without removing it, but you still have to remove it, since the bridge will need to be changed.
How to check the generator on the VAZ-2110 at home? It is not difficult to determine the faulty part of this electric machine. To do this, we disassemble it into its component parts. You may not have to buy the whole thing, but it will be enough to replace or repair the broken part.
- Bearings. To determine the condition of the rear bearing, vigorously rotate it in different directions. If rotation is difficult, there is play or extraneous noise, the bearing must be replaced. Check the front bearing in the same way. To do this, while holding the pulley with your hand, rotate the front cover.
- Pulley. Inspect it for damage and worn teeth. Perhaps it needs to be replaced.
- windings. We connect the probes of an ohmmeter (or a multimeter configured in resistance measurement mode) to the slip rings of the rotor. If its resistance is from 4.5 to 10 ohms, then everything is in order. Otherwise, the whole rotor (anchor) must be replaced.
If now one of the probes is transferred to the rotor housing, then the multimeter should show infinite resistance. If it is close to zero, then the winding is also faulty, "closed to the case."
Similarly, with a multimeter, we check the stator winding for integrity.
Diode bridge (rectifier block)
We connect the positive probe of the multimeter, configured in the diode test mode, to the common bus of the rectifier unit, with the negative probe we touch the opposite terminals of each diode in turn. The resistance should tend to infinity. When changing the probes in places, the resistance is within a few hundred ohms. If this is not the case, then the diode bridge is not working properly and the diode or the entire rectifier unit needs to be replaced.
Voltage regulator
First of all, we examine the regulator brushes. Worn or damaged, they are the most common cause of generator failure and are considered consumable items. The length of their protruding part must be at least 5 mm. Check the smoothness of their walking, the work of the preload springs.
The modern car is literally stuffed with various electrical systems. The power of these systems is directly dependent on the generator, which consists of several components. The most important part of the generator is the generator stator. The operation of the generator and the power supply of the vehicle's on-board system directly depend on its condition. In the event of a generator breakdown, many are in a hurry to change it for a new one, although the generator is easy to sort out and restore almost any part of it. For example, it is quite possible to rewind the generator stator with your own hands.
What elements does the stator of a synchronous generator consist of and the principle of operation
Stator elements:
- Stator winding package;
- Stator core or package;
- Wires for connection output.
The stator itself is made of three windings, three different current values \u200b\u200bare formed in them, this circuit is a three-phase output. The ends of each winding depart from the generator body (they are connected to it), the second end is connected to the rectifier. To concentrate and amplify the magnetic field in the generator, a core made of metal plates is used.
The stator winding of a synchronous generator is located in special grooves, usually there are 36 such grooves. In each groove, the winding is held by a wedge. This wedge is made of insulating materials.
Reasons for the violation of the stable operation of the generator stator
Before you check, you need to find out exactly which generator is installed on your car. This can be found in the manual, but the best way to find out the model and parameters of the generator is by looking under the hood to find the factory tag. On it you will find all the necessary values. If you do not take into account differences in generator models, then the result of the check will be inaccurate. Knowing the basics of electrics, it is easy to identify various problems in the operation of the generator, and other systems of the electrical system.
All stator failures can be divided into two groups:
- Breakage of winding wires;
- Shorting the wire to ground.
If the vehicle is operated in conditions of high humidity or with sudden changes in temperature, the insulation may crack and delaminate. This can provoke an interturn short circuit and even failure of the entire generator, which will cause a sudden discharge of the battery, since the generator will not be able to fully charge it.
Checking the generator stator with a multimeter, how to check with a test light
The generator stator is checked for either an open or a short circuit. To check the resistance, a multimeter is used, in extreme cases, you can use a test light.
The multimeter should be switched to ohmmeter mode, after which its probes are connected to the terminals of the windings. In the absence of a break, the tester will show a resistance of 10 ohms. In the presence of a break, the resistance will show a value tending to infinity. With this result, three conclusions are checked. To obtain more accurate test results, it is better to compare the received data with passport data. You should be aware that inexpensive Chinese multimeters are not able to accurately show the resistance being removed (accuracy is sometimes required up to tenths of an ohm), so you should get a good branded device.
If it is not possible to get any multimeter, but you need to check, you can use a control light (control). It will not show the exact resistance, but it will help to find the gap. Using an insulated wire, a negative charge from the battery is applied to the winding contact. A positive charge should be applied through a light bulb to another contact. If the light is on, then the gap is not found, and the device is functioning properly. This procedure is repeated for all outputs.
Diagnostics for a short circuit is also carried out using a multimeter or test light. The positive probe must be connected to any winding contact, and the negative probe to the stator. This should be repeated with each output. The interturn short circuit is determined by the control lamp in a similar way. Call all conclusions.
Do-it-yourself generator repair
Stator repair usually refers to rewinding the generator stator. For this procedure, you will need an impressive set of tools:
- winding machine;
- Copper wire (may need about 8 spools);
- Rammer;
- Drilling machine;
- Device for drying varnished stator;
- Hammer, a set of screwdrivers and wrenches.
Winding the stator of a car generator is the repair of the stator. First you need to remove the stator itself from the generator. The old winding is scorched, but before that, the generator stator winding must be drawn up, identical to the old three-phase or single-phase winding. When singeing, the magnetic properties of the metal package of the stator do not deteriorate, so you don’t have to worry. When the winding is completely burned, a complete cleaning of the seat should be carried out. Sintoflex insulating gaskets are cut and installed in the grooves.
The winding should be rewound according to a pre-drawn scheme. The linear principle is used in a single-phase generator, and a three-phase stator winding involves a star or delta connection. When rewinding, the wire from the first groove should go immediately to the fourth. First, half of the turns are wound in one direction, then the second half in the opposite direction. The grooves are sealed with the protruding parts of the gaskets, after which the coils must be tapped with a hammer. In order not to damage the winding, you need to use a spacer.
Before checking the operability of the stator with currents, you should make sure that there is no short circuit. If there is a short circuit, then the insulation was laid poorly. You should find the problem area and, using the gasket, eliminate the breakdown.
Before impregnation with varnish, you need to check the dimensions of the rewound assembly; it should not protrude beyond the edges when assembling the generator. The contacts are connected with a thread that will not melt during drying and is placed in a container with varnish. After impregnation of the stator, it is placed in an oven for drying, after allowing the element to flow around. If a suitable furnace is not available, the stator can simply be suspended by installing a heating element from below. When the varnish stops sticking, drying will be completed. When using heat, drying usually takes about 2-3 hours.
With unstable operation of the generator, for many, the solution to the problem is to replace the entire assembly. But if you know how to check all the elements of the generator, then even the stator winding procedure will be up to you.
If you have any questions - leave them in the comments below the article. We or our visitors will be happy to answer them.
There can be at least two malfunctions in the generator stator of VAZ 2108, 2109, 21099 and their modifications. This "cliff" in his windings and short circuit
windings to ground. A sign of a generator malfunction is the disappearance of the charging current. In this situation, after starting the engine, the battery discharge lamp on the instrument panel goes out, the voltmeter needle tends to the red zone. If you measure the voltage at the battery terminals with the engine running, then it will be lower than the 13.6 V required from the generator 37.3701. In some cases, if there is a short circuit in the stator windings, the generator emits a characteristic howl.
Required Tools
- , autotester or other similar device with ohmmeter mode
- In the absence of a measuring device, a test lamp is required (a 12 V lamp with two wires soldered)
Preparatory work
- Remove the generator from the car engine
- and remove the stator
- We clean the stator from dirt
Checking the generator stator 37.3701
Checking for a "break"
We press the probes of the multimeter in ohmmeter mode to the terminals of the stator winding. If there is no "break", the device will show resistance within 10 ohms. If there is a "break" in the stator windings, that is, the current does not pass through them, then the resistance tends to infinity. We check in this way all three conclusions in turn.
checking the stator windings of the generator 37.3701 for an "open" If we use a test lamp, then we apply a minus from the minus of the battery to one of the terminals of the stator winding (using an insulated wire), and a plus through the test lamp to the other output. The lamp caught fire - everything is normal, no - "break". We repeat the operation in turn for all the conclusions.
Checking for a short circuit
We press the negative probe of the multimeter in ohmmeter mode to the stator, and the positive probe to any winding terminal. If there is no short circuit, the resistance on the device tends to infinity. We repeat the operation for each winding output.
checking the generator stator 37.3701 for a "short circuit" When checking the generator stator for a short circuit with a test lamp, we apply a minus from the battery output to the stator, and a plus through the test lamp to any winding output. The lamp lights up - there is a short circuit, no - everything is normal. We repeat the procedure for each output.
Notes and additions
- It should be noted that similar symptoms (except for the howl of the generator) may appear if the voltage regulator, diode bridge, generator rotor malfunction. Since a generator stator malfunction is much less common than a regulator or diode bridge malfunction, it is worth checking them first, and then proceeding to check the stator.
