DIY car generator repair

How to repair a generator and monitor its serviceability

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Why does the engine stall when there is a load on the generator, what could be causing current leakage problems, what should the voltage be, why does the device not work and how to repair the breakdown? Repairing faulty car generators with your own hands is quite a complicated matter, so first we recommend that you familiarize yourself with the main breakdowns of the device. Mechanical faults include damage to the mounting brackets, unit body, wear of the pulley and bearings, pressure springs, etc. There can be many reasons for damage, but in any case, they have nothing to do with the electrical component.

If the car engine does not start and you think that it is the generator that has broken down, then it will be useful for you to learn about the main signs of problems in the functioning of the unit:

A low battery indicator appeared on the dashboard while the engine was running. The light may flash or stay on continuously.
If the device does not operate correctly, when a higher load is placed on the unit than that for which it is designed, the battery comes into operation to support power supply to the equipment. This may cause the battery electrolyte to boil away.
The next symptom is that when you turn on the headlights, you can see how the optics begin to glow more dimly. If you press the gas pedal, which will lead to an increase in the speed of the power unit, the brightness of the optics will be restored to the required level.
The device howls, hums, or whistles. If extraneous sounds begin to appear during operation of the unit, this indicates a problem with its operation, which can be different. The generator also gets very hot.
The car engine stalls from time to time for no apparent reason. A malfunction of this kind may indicate that there is a lack of voltage in the on-board network necessary to power electrical equipment. If the battery is fully charged, then most likely the cause is the generator.

Now let's look at the possible causes of problems that may require removal, disassembly and repair of the car's generator unit:

Pulley damage or wear. If we are talking about serious problems and significant damage to the pulley, then it will be easier to replace it. In some cases, repair and restoration are allowed, but it is best to replace the device.
Damage or natural wear of the slip rings, which may be damaged.
Problems with the control device. The voltage regulator is designed to equalize the operating value in the car's electrical network; its failure will lead to voltage surges in the network.
Failure of the diode bridge of the unit. When diodes fail, the first symptom of a breakdown is the absence or too weak of a spark on the spark plugs, and the battery capacity may also be reduced.
Closing the turns of the stator winding. Sometimes rewinding the winding can solve the problem, but often it is easier to simply replace it.
Bearing wear. If the bearing elements wear out or break, the unit will produce additional noise.
Damage to the power supply circuit.

Troubleshooting methods

How to disassemble and how to repair the device? Below are some basic troubleshooting tips.

These tips are relevant if you know the main causes and signs of breakdowns:

A low battery charge or lack of charge may be due to a failure of the safety device or its poor contact with the socket in the block. It is necessary to check the fuse itself for functionality and make sure that it is in good contact with the socket. Sometimes the reason for the lack of charge is due to wear on the brushes on the voltage regulator. If such a problem occurs, the regulator itself will need to be replaced.
To diagnose the voltage regulator brushes, you can perform a visual check. If the voltage surges are associated with a short circuit or open circuit, then you will have to use a tester to check.
To check the condition of the diode elements, you will need to remove and disassemble the unit; failed components must be replaced by re-soldering. If the winding is damaged, as mentioned above, it needs to be rewinded, but it is quite difficult to do this task with your own hands. It is better to entrust the rewinding procedure to specialists. You can understand exactly which diodes have failed and need to be replaced using a tester.
When the fault lies in a break in the electrical wiring near the slip rings or in the unsoldering of the ends of the winding, it is necessary to replace or repair the rotor mechanism.
The repair begins with unwinding one turn of wire. The damaged end must be resoldered. The ring itself can be cleaned with sandpaper, but it is advisable to use a fine-grained version. If you notice that there are more serious damages on the ring, you can remove them using flat needle files. As for the replacement itself, it is usually advisable to perform it in case of complete damage to the rings.
If a car generator makes a loud noise during operation, then, as we have already said, the reason should be sought in the rotor bearings.
For diagnostics, it will be necessary to dismantle and disassemble the unit. If during the inspection you see that the bearing parts are worn out, and there is play when turning them, then the devices need to be replaced. If there is play, but it is not critical, then you can try to remove the bearings, wash, lubricate and reinstall. Lubrication is very important because lack of it will kill the bearing very quickly. If, as a result of assembling the unit, extraneous sounds disappear, then we can assume that the repair was completed successfully.
If the car battery low indicator light on the instrument panel continues to light, then there is a possibility that the reason lies in a breakdown. Namely, this means breakdown of the diode element of the bridge. To gain access to the diode bridge, you will need to unscrew the winding nuts and remove the nut securing the positive terminal. After completing these steps, you will be able to access the bridge, which is either being replaced or repaired. Often changing the bridge is faster and more profitable (video author - Eduard Grinenko).

DIY replacement instructions

Sometimes self-repair of the unit is impractical, so car owners have to change the device. Let's consider the replacement procedure using the Lada Kalina car as an example.

Tools and materials

To successfully perform the replacement, prepare the following tool:

wrenches for 8, 13 and 19, for greater convenience, use box and open-end wrenches;
ratchets with heads of similar sizes;
extension cord with a crank (the author of the video is the AndRamons channel).

Stages

The replacement procedure must be carried out taking into account the recommendations and requirements of the manufacturer, which are specified in the service manual. Before you start replacing, be sure to read the manual.

So, how to remove and replace the unit yourself:

To begin, turn off the ignition and disconnect the wire with the terminal from the battery.
Open the hood and loosen the belt tensioner nut, then remove the device.
Next, disconnect the plug fixed in the seat using a plastic latch; to do this, you need to press it and pull it to the side. Usually it is removed without problems. You also need to disconnect the terminals with the wires located under the rubberized cap; having done this, you can pry up and unscrew the nut.
After this, the fixing nut of the upper part of the unit must also be unscrewed. Before doing this, you can use a wrench and then use a ratchet.
Tap the protruding screw lightly until it begins to move. Remove the bolt from the reverse side, shown in detail in the photo.
Now you can unscrew the lower bolt securing the unit; in this case, the dismantling procedure is performed in a similar way. The only difference is that when unscrewing it is necessary to support the nut from the back side, since during unscrewing they can turn.
When removing the stem you need to be most careful because this is where the bushings are located. When removing, be sure to support the bushings, otherwise they may fall and become lost. Hold the body of the unit to prevent it from falling, and use your other hand to remove the screw.
After completing these steps, you can remove the unit from the engine compartment. When dismantling it, you should turn it slightly from one side to the other - this way you can find the most optimal place for removal. Now all you have to do is replace the generator unit with a new one; all further assembly steps are carried out in the reverse order.

Photo gallery “Changing the generator on Kalina”

Recommendations for node maintenance

Timely repair and maintenance of the unit are the main aspects that will increase the service life of the device.

What nuances should be taken into account:

Periodically check the voltage level in the machine's electrical network.
This parameter may indicate a lack of battery charge or incorrect operation of the generator. Voltage diagnostics are performed using a multimeter. With the engine running, you need to connect the tester probes to the battery terminals. If the test shows that the voltage is between 13.8 and 14.2 volts, then everything is working fine. If the obtained value falls outside this range, then the problem must be looked for either in the battery or in the voltage regulator.
Always keep an eye on your headlights. If the light from the optics has become dimmer, but when you press the gas it is restored, then check the voltage regulator. The cause of the malfunction may also lie in the rectifier unit (diode bridge).
Regularly check the condition of the drive belt - it should be properly tensioned and not overtightened. Over-tightening the belt leads to accelerated wear and incorrect operation of the unit as a whole. The drive belt is classified as consumables, so it must be changed periodically. If cracks appear on the surface of the belt and threads begin to peel off, this indicates that it will soon have to be replaced.
Listen to how the unit works. Bearings are also consumable devices, so if noise that is uncharacteristic of the operation of the generator appears, they must be checked. If parts are worn out, they must be replaced.

Video “The principle of operation of a car generator”

An object lesson with a detailed description of all aspects on the principle of operation of the unit is given in the video below (the video was published by Mikhail Nesterov).

Do you have any questions? Specialists and readers of the AVTOKLEMA website will help you ask a question

Source: https://avtoklema.com/alternator/remont-generatorov-4026/

DIY generator repair

Any driver knows that the generator is designed to generate electrical energy and supply power to the vehicle's on-board network. Without a generator, the car can only be used for a while (until the battery runs out), which is why the serviceability of the generator must be at the highest level.

Generator malfunctions and ways to eliminate them

As you know, repairs consist of eliminating problems that have arisen. The most important and fundamental malfunction of the generator is low voltage or its absence. We usually find out about this if the battery suddenly runs out, the car stalls, or the corresponding lamp on the car’s dashboard comes on.

To verify this, try removing the battery terminal while the engine is running and pay attention to the behavior of the car. If it stalls or the engine starts to stall, then the generator is faulty. Finally, you can connect a voltmeter to the battery terminals.

Normal voltage should be in the range of 12.5 - 14 volts.

There are many reasons for this malfunction. All problems and ways to solve them will be described below:

Loose or broken alternator drive belt

In this case, it needs to be replaced or tightened. Tensioning is done by loosening the adjusting fastening nut and tightening it after tensioning the belt.

The tension is adjusted by tilting the generator in the direction opposite to the engine. The unit is fixed in this state, after which the nut is tightened with a wrench.

To rotate the generator, it is also necessary to loosen the lower nut intended for axial fastening of the unit.

If the belt breaks, you need to loosen both fastening nuts, tilt the generator and put on a new drive belt. After this, the belt is tensioned and the nuts are tightened with sufficient force.

Brush assembly wear

Brushes are designed to apply or remove tension from the rotor slip rings. If they are worn out, then contact with the rings is lost. Thus, the charging current of the generator also disappears.

In this case, disconnect the battery terminal, pull out the plug with wires from the connector of the generator or brush assembly and unscrew the two screws securing the brushes. Pull out the brushes, install new ones in their place and tighten the fastening screws.

All other operations are performed in reverse order.

Open field winding

In this case, it is necessary to disassemble the generator that has already been removed from the car. To do this, remove the brushes from it and unscrew the four nuts on the unit body. After the nuts are unscrewed, remove the mounting studs in the form of long bolts and separate the stator parts.

The stator housing is separated into two parts, the rotor is pulled out. Depending on the type and design of the generator, the location of the field winding can be either on the rotor or on the stator. After detecting it, measure the winding resistance.

Resistance standards are indicated in the technical tables of your generator model, and if the device readings deviate from the norm, the winding must be replaced.

In addition, in addition to a winding break, a short circuit may occur. In this case, its insulation is faulty. However, it is also subject to replacement.

After replacing the winding, reassemble the generator in reverse order and install it on the car.

Video - Do-it-yourself diagnostics and repair of generators

Diode bridge faults

The diode bridge is also a weak point of the generator and its repair or replacement is carried out on a removed and disassembled car generator.

Before carrying out repairs, it is necessary to carefully inspect the part. Most likely, the contacts from the semiconductor elements were simply unsoldered on it.

In this case, they are simply soldered into place and all the parts are installed back. Another thing is when burnt marks appeared on the surface of many diodes.

In this case, it is best to replace the entire bridge and install a new element on the generator stator.

It is worth saying something about the features of diodes. These elements are designed to rectify voltage and have conductivity in one direction only. If this conductivity is broken, it means that the semiconductor is faulty and requires replacement. It is impossible to detect this by external examination, but there is the following way:

Using a lamp tester, check the conductivity of all bridge diodes. To do this, one contact of the tester is applied to one side of the diode, the other to the other. If the lamp does not light, then swap the contacts.

Only in one of the positions should the lamp light up and this applies to all other diodes. If the lamp does not light up at all, or lights up in both directions, then the diode needs to be replaced.

It is unsoldered, squeezed out, a new one is installed in its place and the contacts are soldered.

Other malfunctions . These may include disruption of various contact connections. In this case, the contact surfaces are cleaned or the entire contact is replaced. It is worth recalling that poor contact, at least in one place, leads to a decrease in the efficiency of the power supply or failure of the entire unit.

It's worth returning to the alternator belt again. Even if it is tensioned normally, feel it for moisture. It is possible that oil or antifreeze has dripped onto it, and it simply slips, disrupting the normal transmission of torque to the generator pulley. This also happens.

Separately, one can note the increased noise when the generator is running. The culprit for this noise is most often the rotor shaft bearing. Its noise indicates that it has worn out and needs urgent replacement.

It is highly not recommended to delay this matter.

The fact is that imbalance of the shaft will lead to contact of the rotor with the active steel of the stator, a short circuit will appear, which will also affect the voltage level of the on-board network.

This problem can be fixed. To do this, the generator is disassembled, the rotor is removed along with the bearing, which is then pressed out of the rotor. After this, a new bearing is mounted using special equipment, and the rotor is installed in its place.

This is all that is associated with generator malfunctions. If after eliminating the above the problem does not disappear, then you need to look for it elsewhere.

Source: http://VipWash.ru/elektrika-avtomobilya/remont-generatora-svoimi-rukami

DIY Car Alternator Repair, Maintenance Manual, Overhaul Equipment

A car generator is an electrical device that supplies the vehicle’s on-board network with electric current by converting mechanical energy into electrical energy. They come in different capacities (trucks need very powerful generators to charge their batteries).

One of the main functions of the generator is to charge the battery, which without a generator is discharged in half an hour. If the alternator fails, the vehicle's electrical equipment will discharge the battery and further engine operation will be impossible.

In order to prevent such a situation, you should consider in detail the design of the generator, the causes of breakdowns and failures.

The generator is a rather complex device. Without knowing the principles of its operation, it will be difficult to understand its breakdowns or unstable operation. Repairing a car generator at a specialized car service center will be quite expensive, especially since the cause of the breakdown may be in one unsoldered wiring, and many unscrupulous servicemen will force you to pay for a major repair of the generator.

Reasons for unstable generator operation

The battery is not charging;
The generator produces minimum voltage;
The charge is too high;
When the charging process occurs, the light on the panel flashes;
When the generator is running, extraneous squeaks and squeaks are heard.

Knowing the main problems that can cause a generator to malfunction, you can begin to calculate them. If the generator stops charging the battery, it is possible that:

Any of the contacts has moved away;
The fuse has blown;
The generator brushes have worn out;
The generator relay burned out;
Short circuit or open circuit in the stator or rotor.

Alternatively, you can have the rotor or stator repaired, or you can buy a new winding and repair the generator yourself. Replacing a winding is essentially repairing a stator or rotor.

If a break occurs in the slip rings, you can get by with local repairs; to do this, you need to unwind the turns to the damaged area and replace the removed piece with a new one, soldering it to the break point. Often only the end of the winding on the rotor is unsoldered. It just needs to be soldered back.

However, when repairing a rotor or stator, the maintenance instructions strongly recommend completely rewinding the stator and rotor. When rewinding parts, do not forget that all slip rings must be carefully processed with a file.

Generator Noise Elimination

Most generator noise is caused by wear on the generator bearing. The bearing located on the rotor is checked for play.

If they are not detected and the bearing continues to creak, the problem is a lack of lubrication in the bearing.

The bearing is dismantled, washed in gasoline, lubricant is added to it (about 30 percent of the bearing volume), and then installed in place. This operation will eliminate all extraneous sounds associated with the operation of the bearing.

Weak or overcharging battery

The main cause of this malfunction is the battery relay. If this problem occurs, it should be replaced. Sometimes there is a problem such as diode breakdown.

When the signal light is on and the current is normal, the problem, as a rule, is the breakdown of several diodes. They are located on the diode bridge.

In order to get to them, you need to unwind the generator and remove the stator winding fastening. At the output fastener, the nut is released and the diode bridge is removed.

When performing this work, you can immediately change the winding on the stator, eliminating problems in the future.

Detailed DIY generator repair guide

Repairing car generators is a lengthy process that will require special repair equipment.

Test bench;
Ammeter;
Rheostat;
Voltmeter.

If you do not have access to a test stand, you can make it yourself, or do without his help.

Removing and disassembling the generator

Remove the generator from the engine compartment;
After unscrewing the fasteners, remove the brush holder and voltage regulator;
Remove the tension bolts;
Having disconnected the phase windings from the wires on the rectifier, you need to remove the stator cover;
Lastly, the shaft pulley and the front cover of the generator are removed. To do this you need to use a special puller.

When dismantling the generator, you should avoid excessive force when unscrewing soured bolts. Thread failure entails a very unpleasant procedure for cutting new threads and turning new bolts. It is better to fill the problem screws with Vedashka and leave for a couple of hours.

Replacing brushes and generator relays

If you have to replace the alternator bearings, it's time to replace the brushes as well. It is unknown when they were last changed or if they were changed at all.

To ease your conscience, you can remove the brushes from the generator for a visual inspection, but it is better to change them immediately, because you are unlikely to want to climb into the generator again.

When replacing a relay, the main thing when choosing is to find one that is recommended by the manual for your car. It is best to remove the old one and pick up the same one.

Generator Maintenance

Like all other components and assemblies of a car, the generator requires care and periodic maintenance. It is necessary to change the bearings as they wear out, and the generator brushes. Make sure that large amounts of dirt, dust and especially water do not come into contact with the generator.

Often, due to careless maintenance, oil or antifreeze can get onto the generator. You should avoid this and if technical liquids get on the generator, promptly remove them with a rag.

For the generator to function properly, the V-belt must be well tensioned, but not overtightened.

Manufacturers recommend carrying out a preventive inspection of the generator every 15-20 thousand kilometers. If you properly maintain the generator and monitor its condition, it can last 1600-200 thousand kilometers. However, a preventive inspection is not a quick look at the generator; it involves a complete disassembly and diagnosis of the generator components.

Generator assembly

Assembly takes place in the reverse order of disassembling the generator. The only assembly nuance is the desirability of using a special caliber, with two diameters (12 and 22 millimeters). When tightening the generator pulley nut, it is important not to exceed a tightening torque of 88 newtons per meter.

Emergency situations during generator repairs

Broken screw threads or threads in the generator cover. To avoid this problem, you should control the tightening force of the screws;
Replacing generator rotor bearings. Even if they did not creak during operation, the bearings may simply fall apart when removed;
The battery charging lamp relay may need to be replaced. Typically, this relay should be looked for in the area of the right front wheel (above it).

When repairing a generator, it is important to accurately identify the cause of the malfunction.

If it's the brushes, insufficient belt tension or a faulty relay, replacing them won't be too difficult. If you have to replace or winding the rotor or stator, it is easier to entrust this procedure to the specialists of service centers for repairing generators. Knowing the cause of the breakdown, you will be sure that you will not pay extra money.

However, if you are confident in your abilities, you can do a complete repair of the generator yourself. A generator after repair, especially a major one, is practically a new device.

Source: https://SwapMotor.ru/ustrojstvo-dvigatelya/remont-generatora.html

Do-it-yourself generator repair - detailed instructions

A car generator is a device that takes the mechanical energy of the engine and converts it into electrical current, thus providing electricity to the rest of the car's components. The generator charges the battery and powers the car's engine.

Therefore, the “engine-generator” connection should not be interrupted, because a non-working generator is a battery that does not receive a charge and, accordingly, the main organ of the car does not work.
Replacing a generator will entail significant financial costs.

Therefore, if you have all the necessary tools and knowledge of the devices of the car’s engine compartment at hand, then you can fix the breakdown yourself (read about what to do if the car does not start - the starter turns in our other article).

So the generator is broken. What malfunctions can cause this device to malfunction? Let's look at them:

The generator produces current at a very low voltage.
The generator does not produce any electrical current at all.
A device failure is displayed on the dashboard as a flashing light.
The generator charges above the optimal rate.
The operation of the generator is accompanied by extraneous noise.

Before you start repairing the generator yourself , you need to check its technical condition and disassemble the unit into parts.

Before disassembling the generator, check the condition of the belt and its tension and make sure whether you are expecting a replacement generator belt in the near future (read also how to replace the timing belt on a VAZ 2109). The test consists of pressing your finger on the middle of this part of the generator.

If the belt is in good condition, it should not fall more than half a centimeter when pressed. It is worth noting that the new belt should not bend by more than 2 mm. If the belt is not worn out, but the tension is weak, then the deficiency can be corrected by tightening the generator belt.

Also rotate the tension roller of the generator; if it turns with difficulty and creaks, then you will need to lubricate it with oil, or install a new roller instead.

The technical condition of the generator can be checked using the following measuring instruments:

ammeter;
voltmeter;
rheostat.

Rotor speed is measured using a tachometer (usually located next to the speedometer on the instrument panel). During normal operation of the generator, the readings of this device should not be less than 2000 rpm, while the norm is 5000 rpm.

Do-it-yourself generator repair - reasons for repair

Let's look at the reasons that can cause generator failure. So, if the generator does not produce a charge, then the reasons for this may be the following phenomena:

The fuse or contacts have blown.
The generator brushes are broken or worn out.
The regulator relay has failed.
Due to a winding short circuit, a break occurred in the stator or rotor circuit.

In order to correct the first three malfunctions from the list, you simply need to replace the worn parts of the generator, having first, of course, disassembled it.

How to remove the generator and disassemble it

First of all, remove the brush holder along with the voltage regulator, carefully unscrewing all the fasteners.
Remove the tension bolts and then the cover with the stator.
Remove the cover from the stator, first disconnecting the phase windings from the output wires on the rectifier unit.
Next, remove the pulley from the shaft and the front cover of the generator using a special puller.

The generator is assembled in the reverse order.

If the winding shorts, you will need to take more serious action than simply replacing the part. So, a broken winding can either be repaired or replaced with new wires. Often the winding breaks near the slip rings.

In addition, a breakdown may occur due to unsoldering of one of the ends of the winding. Such a malfunction can be repaired by unwinding the turn in the area of the break back from the rotor winding. Next, the broken end of the winding must be removed (unsoldered) from the slip ring and the previously unwound wire must be soldered there.

The desoldering is very easy to fix by re-soldering the wiring.

A weak or too strong generator charge is indicated by a damaged relay, which must be replaced when repairing the generator.

If checking the generator voltage shows that the device is working properly, but the indicator on the instrument panel is blinking, then most likely one of the diodes that are responsible for powering the light bulb in the indicator has failed. These diodes are located in the generator itself, and replacement is carried out after disassembling the device.

Noise unusual for a generator may be indicated by wear of the rotor bearing. If upon inspection it is discovered that the generator bearing is worn out, it will need to be replaced. If the strange sounds of the generator are associated with the lack of play in the bearing, then you can simply fill it with oil, after first rinsing it in gasoline. Extraneous sounds will then disappear.

Thus, you can do generator repairs on your own even in your garage (just like engine overhauls, in fact). When checking and replacing device parts, follow safety precautions and be careful, because the electrical system should not be damaged.

Generator repair: video

Source: http://autoremka.ru/dvigatel/remont-generatora-svoimi-rukami-podrobnaya-instrukciya.html

Do-it-yourself generator repair - automobile portal of Ufa and the Republic of Belarus

Good maintenance, which any car requires, will allow it to serve its owner for many years without serious problems. You just need to monitor the serviceability of the main components and systems. These include a converter of mechanical energy into electrical energy. Replacing and repairing car generators is one of the main operations of service center workers.

After all, without power supply, the comfort of the vehicle disappears, and it turns into a horseless cart made of stamped metal. The generator rarely stops functioning immediately. It usually gives the owner signals for quite a long time by “winking” its sensor in red and making noise from under the hood. You must carefully study the operating manual of the machine.

Weak or overcharging of the battery is also a symptom of its suffering. Checking it will show a number significantly less than 13 Amps on the multimeter. Then you need to seek help from specialists. Although, if a car enthusiast feels sufficiently prepared and experienced to try to find and fix the breakdown on his own, then he can begin to master the profession of a car mechanic.

Of course, technologically repairing generators is not difficult, but it is better to stock up on a sufficient set of tools and enlist the support of a friend experienced in this matter. The soldering skills of at least one of your friends will be very useful. Otherwise, you will have to invite a third one. You can start the event. It should be led by the most experienced member of the team.

Preliminary identification of the cause of the breakdown

Some idea of the “disease” of the generator can be obtained based on the characteristics of its new behavior. The car manual contains a lot of information.

Noise during operation indicates wear of the bearings. If one bearing breaks, it will make a small sound. If two bearings are involved, the generator will rumble.
The regulator indicator flashes red and charging is normal. Most likely, the relay in the electrical circuit is broken.
Insufficient battery charge can be explained by worn-out or broken brushes, diodes, relays, or voltage regulator. Or there is a short circuit in the windings of the unit.

Before removing the generator, be sure to first remove the terminals from the battery, then disconnect all wires from the device itself. Before dismantling it, you need to check the tension of the drive belt and the condition of the tensioner. If it sags a lot, you can try to tighten it by loosening the fastenings and moving the unit along the guides.

Or use the tensioner adjustment. It is attached to the motor and rotates using a bearing. Many models do not have it. Where it is, you need to loosen the adjuster nut and increase the pressure of the tensioner on the belt. Checking the result by pressing on it should give a feeling of sufficient tension.

It was not possible to achieve sufficient tension - the belt needs to be replaced. Now you can safely remove the generator from the belly of the car and take it to the “operating table” for opening. It is advisable to have a surface lined with white paper nearby. It will be convenient to place small parts (nuts, bolts) on it to prevent their loss.

This must be taken very carefully, because some elements are made of insulating materials. The instruction manual describes these nuances. Replacing them (if the old ones are lost) with metal parts when servicing the generator is carried out will lead to its burnout at the first start-up with no chance of another repair. After assembly, the table should be empty.

Generator disassembly and repair

1 – “negative” brush; 2 – brush holder; 3 – “positive” brush; 4 – neutral wire plug block; 5 – insulating bushings of the contact bolt; 6 – rectifier block; 7 – contact bolt; 8 – stator; 9 – rotor; 10 – inner bearing mounting washer; 11 – drive side cover; 12 – fan assembly with pulley; 13 – outer bearing mounting washer; 14 – front rotor bearing; 15 – spacer ring; 16 – coupling bolt; 17 – clamping sleeve; 18 – cover from the side of the slip rings; 19 – buffer sleeve; 20 – bushing

Before the procedure, you need to hold the pulley, twist and shake it. If it rotates with resistance, and when loosened it dangles and knocks, then the bearing needs to be replaced. When repairing a generator with your own hands, you need to know that the front bearings often become unusable.

If the rotor moves normally and the rotor is firmly positioned in the housing, after removing the bearings, they will need to be “bathed” in gasoline and lubricated with oil. Both bearings must be subjected to this procedure. They will last for a long time. High-quality generator repair service requires the installation of both new bearings.

The back cover is removed first. The most common causes of unit failure become visible. You may notice areas of loose or burnt contacts or parts. To repair them, you will need a soldering iron and solder.

relay regulator

Next, you need to remove the relay with the brush assembly (often they are enclosed in one housing) and the diode bridge. The voltage regulator needs to be checked. Then, each generator repair involves removing the rotor and stator. You need to carefully examine their braid. If traces of severe damage are visible, it is better to replace the burnt part.

A soldering technician can take on repairing the generator rotor, replacing a relay, or restoring the stator, but only in case of minor interference. He can service the windings and burnt contacts. His job will be to “ring” the diodes on the bridge, the voltage regulator and replace them if they are found to be faulty.

Careful repair of generators of any machines requires inspection of the current collector rings and relay brushes. If the integrity of the brushes and rings is maintained, they require cleaning and slight grinding. If the brushes protrude by less than half a centimeter, the part is replaced with a new one. All contacts must be cleaned, parts must be cleaned of dirt. Lubricate friction points with suitable oils.

Generator assembly

The sequence of actions is the reverse of that used in the previous process.

During assembly, you must carefully ensure that each part falls into place and is secured with sufficient force. Fasteners should only be used.

The assemblers should always have a manual with diagrams of this process in front of them so as not to make mistakes.

It is unacceptable to omit or add anything on your own. Repairing a generator with your own hands does not tolerate brute physical force. For example, when installing a diode bridge and a voltage regulator, the new brushes may break. We must act carefully. If necessary, a rubber-coated hammer may be used. Including when installing bearings in place.

It is recommended that all bolts and studs are not fully tightened with a screwdriver. The finishing turns must be done manually until resistance + half a turn of the screwdriver. As a result, only the repaired generator and replaced old parts should remain on the table.

Testing of serviced generators is usually carried out on a bench. If the test is passed without any complaints, the unit can be installed back into the car.

We recommend watching videos on the topic:

Source: http://v-transport.ru/remont-generatora-svoimi-rukami-obsluzhivanie-i-zamena/

DIY generator repair

Do-it-yourself generator repair consists primarily of checking its technical condition and disassembling the generator. You should check the condition of each of its parts.

It is advisable to check the technical condition of the generator using an electric drive, voltmeter, tachometer, load rheostat and ammeter. In this case, the generator rotor speed must be in the range of 0-5000 min-1, and the rheostat must be designed for a current of 60A.

When carrying out the test, the minimum rotor speed should be determined to reach 12.5 V (with and without load). The rotation speed when reaching 12.5 V should not exceed 1000-1100 min-1 without load and 2000-2200 min-1 with load.

In what sequence to disassemble the generator?

When repairing a generator with your own hands, first of all you should know the correct sequence for disassembling the generator: first of all, you should remove the brush holder with the voltage regulator, having first unscrewed all the fasteners,

then remove the coupling bolts and remove the cover along with the stator.

Next, you should remove the stator covers; to do this, you need to disconnect the phase windings from the terminals on the rectifier unit.

Remove the fastening nut from the pulley and remove it from the shaft, and only then remove the front cover of the generator (be sure to use a puller).

Accordingly, you need to assemble the generator in the reverse order.

First of all, you should check the condition of the generator parts: check the rotor field winding, stator windings, rectifier unit diodes.

You can check the rotor field winding using an ohmmeter. To do this, attach its probes to the armature contacts and check for breaks according to the degree of resistance. The stator winding is checked using a battery and an indicator. Check for short circuit or open circuit. The test is also carried out with an ohmmeter.

In the absence of malfunctions, the resistance on all windings should have a deviation of no more than 10%. To check the diodes of the rectifier unit, you will need a lamp and a battery. A faulty diode allows current to flow either in both directions or not at all. If there is any malfunction of the unit, it should be replaced.

Testing the voltage regulator is carried out by connecting a power source (two batteries totaling 24 V) and a potentiometer. When the voltage is set to 12V, the lamp should light up; when the voltage increases to 14-15V, the lamp goes out. If this does not happen, then the regulator contains a breakdown and should be replaced.

Don't forget to check the degree of wear on the rotor rings and bearings. If the bearings acquire an excessive degree of play, they should be replaced. And rings with a degree of wear of more than 0.5 mm should be sharpened.

Source: http://vsepoedem.com/story/remont-generatorov-svoimi-rukami