How to replace a diode in the diode bridge of a VAZ 2110 generator

When the generator is turned on, it produces direct current. But to power all consumers in the car and recharge the battery, alternating current with a clearly defined frequency is required.

The diode bridge performs the functions of converting direct current into alternating current. This device is also called a rectifier.

Element appearance

Diode bridges can have different designs. However, cars are mainly equipped with three-phase rectifiers. This is due to the important advantages that they possess. Namely:

• The output produces the most pulsating voltage;
• Three-phase devices are excellent for half bridges and diode bridges;
• Their design allows the additional use of a capacitor - a current filter.

Checking and replacing the diode bridge of the VAZ 2110 generator with your own hands

Once it starts working, the generator begins to produce direct current, but to operate all the devices in the car, as well as to charge the battery, an alternating current is needed (pulsating with a clearly defined frequency).
Diode bridge 2110-3701315 “StartVOLT” for VAZ 2110-2172 generators produced by KZATE

It is the conversion of current that the diode bridge of the VAZ 2110 generator, which is also called a rectifier, is engaged in. And although there are many design options, the cars are equipped with three-phase ones, the advantages of which are obvious:

• At the output they create the smallest ripple voltage;
• Three-phase rectifiers are suitable for bridge and half-bridge diodes;
• They make it possible to install an additional capacitor - a current filter.

Design

In the original (factory) configuration, the diode bridge of the generator on the VAZ 2110 is a monolithic structure. It is quite reliable, inexpensive, compact, and has, one might say, only one drawback: if one of the diodes burns out, its local replacement is impossible; you need to buy a new factory bridge and install it.

In the event that a check shows that the diode bridge is no longer functioning and needs to be replaced, it is quite possible to assemble it from various diodes. If the factory layout provides four or six diodes, then during self-assembly you can install an additional one.

Many car enthusiasts do this. In addition, as a rule, in the case of self-assembly, diodes are installed not in the factory layout, but a little stronger, so that they do not burn out so quickly.

But since it is impossible to qualitatively test such a rectifier, during “home assembly” you can damage the generator, after which it will be necessary to replace not just a cheap part, but the entire assembly.

Causes of breakdowns

As numerous checks show, the main cause of breakdowns is factory. Here, first of all, you need to pay attention to the shell in which the diodes are located. If it is aluminum, it is better not to take such a unit. Much more reliable is steel.

In addition, if the seller does not provide a guarantee, you should be wary. According to reviews on the Internet, the most unreliable diode bridges are made in Belarus.

• Another reason is moisture ingress, which results in oxidation of the space between the diode itself and the housing;
• Contact of oil or other working fluids of the VAZ 2110 on the surface;
• If you reverse the polarity of the battery while lighting or charging, the diode bridge can easily “fly out”;
• You can also suspect that the VAZ 2110’s rectifier is failing if the battery stops charging.

What causes the need to replace diodes

Someone will say that it is much easier to take and replace the diode bridge completely. However, the cost of a diode bridge for a foreign car varies from 1000 to 4000 rubles, sometimes the price is even higher. Depends on the brand of the car, the type of generator, whether it is an analogue or an original. New diode bridge or under contract. You ordered a diode bridge online, you thought it was new and original, but an unscrupulous storekeeper put a Chinese equivalent in your package. Go figure it out right away.

Many, having replaced the diode bridge on their generator, prefer not to throw away the old one, but to repair it and leave it in their stash.

The question is that not everyone can independently remove a bad diode and press in a new one. It is best to turn to the services of professional craftsmen at a service station. The diode bridge repair process is streamlined and will not take much time.

Source

Examination

Using a multimeter it is very easy to check the serviceability. Need to:

• Place the positive probe of the multimeter at the positive diode bus;
• Do the same with the negative probe and the “-” diode output;
• This test, if the diode bridge is working properly, should give readings close to infinity. If this is not the case, there is a malfunction and needs replacement;
• Now we swap the probes (put plus to minus and vice versa);
• Let's look at the readings. If the unit is working properly, the readings should be several hundred ohms;
• To check the additional diode, perform the same steps as described above.

Replacement

When dealing with any component related to electrical equipment, you need to start by de-energizing the VAZ 2110. So, we proceed according to the algorithm:

1. Disconnecting the battery (remove the “-” terminal);
2. Remove the pink wire that turns on the generator. To do this, you need to unscrew the nut from the positive bolt;
3. Loosen the upper and lower nuts, and also unscrew the tension bolt, remove the belt;
4. Turn the generator 90° and remove the lower mounting bolt;
5. Clean all connections, as well as the rectifier housing itself;
6. Clean the inside of the ring very thoroughly;
7. Replace the generator diode bridge with a new one;
8. Reassemble all parts;
9. Check the functionality of the generator.

Source

How to replace a diode in a generator diode bridge

As you know, a car generator is designed to provide power to all electrical equipment in the car when the engine is running. This unit in domestic “tens” consists of many elements that ensure its optimal operation. One such device is a diode bridge. What functions does it perform, what do you need to know about its malfunctions, and how is the diode bridge of the VAZ 2110 generator replaced? You can find answers to these and other questions below.

If a malfunction is detected

Diodes are attached to the wafers by pressing into a hole of a smaller diameter, so replacing a faulty semiconductor yourself is a troublesome task that does not guarantee 100% success. Diode bridges for domestic cars are inexpensive, so if a fault is detected, it is replaced with a new one.

Rectifier units of modern foreign cars cost a lot of money, so replacing the diode in such a bridge is economically justified. It is better to entrust this procedure to a specialist.

Faulty diodes are replaced with elements with the same power rating. Power reduction is not acceptable.

The quality of operation of the entire electrical system of the car depends on the condition of the diode bridge. If the previously listed signs of malfunction appear, you must immediately diagnose, repair or replace it.

Description of the diode bridge on the “Ten”

How is the diode modified and installed in the device? For what reasons can a bridge fail? To begin with, we suggest that you familiarize yourself with the description of the part. If you dismantle the generator assembly from the car and remove the cover, you will be able to see the diode bridge (DM), which is located immediately behind it.

Purpose and functions

What functions does the DM perform:

1. The primary task of the device is to convert alternating current into direct current.
2. The DM also performs the function of blocking current from entering the stator winding. In this case, the device actually performs the one-way valve option.
3. In addition, the DM is designed to increase the safety margin of the generator unit. It allows you to protect the mechanism from the effects of adverse factors and contamination on the device, and this, in turn, can negatively affect the functionality of the mechanism as a whole.

Device

As for the device, in the factory configuration the DM for the “tenth” generator is a monolithic structure. This design, as a rule, is quite strong and reliable, is characterized by its small size, as well as a relatively low price. The only drawback characteristic of factory-made DMs is that if one of the diode elements burns out, local replacement of the damage will not be possible. That is, the car owner will have to completely change the factory axle with his own hands.

As for the design features itself, the DM consists of:

• two aluminum plates;
• spacers made of plastic;
• as well as nine diodes, which are connected to each other by soldering into one structure, that is, a bridge.

Design features of the generator

Structurally, all generators installed on cars consist of a rotor, stator, covers cast from aluminum alloy, voltage regulator, rectifier unit (diode bridge) and brush assembly.

The rotor is a shaft on which the excitation winding is installed between two pole halves - magnetic cores. There are six beak-shaped protrusions on each half of the magnetic circuit. As the rotor rotates, the beaks of the magnetic circuit alternately cross the magnetic field of the stator, inducing a current in the winding.

When voltage is applied to the rotor of the brush generator, the beaks directed towards each other are magnetized. One half is magnetized in the “south” direction, the other in the “north” direction, and when the rotor rotates, the magnetic field changes cyclically from “north” to “south”, exciting an electric current. In a generator that does not have a brush assembly in its design, the beaks of the magnetic circuit are magnetized in a similar way, and at the same time have their own rotation. In practice, such generators have not found widespread use due to their unreliability, complicated design, large dimensions and weight, as well as frequent breakdown of magnetic circuits, leading to the destruction of the entire generator.

Possible malfunctions: signs and causes

As stated above, the purpose of diode elements is to convert alternating voltage to direct voltage. If one of the diode elements fails, then its malfunction may be indicated by such a sign as a decrease in the voltage level, as well as power in the vehicle electrical network.

For what reasons may problems occur in the operation of the DM:

1. Manufacturing defects. As practice shows, many modern DM manufacturers use aluminum shells of fairly low quality in their production. Accordingly, this affects their reliability as a whole. That is why it is recommended to use DM equipped with steel shells, since this directly affects the service life.
2. Moisture gets inside the device. Regular exposure to moisture can cause oxidation, in particular, on the surface between the device body and diode elements.
3. Engine fluid getting into the unit is one of the most common causes. Exposure to lubricant can lead to disruption of the functionality of the device as a whole, especially if it gets inside the generator unit, directly on the DM.
4. Another reason why DMs on “tens” often fail is the polarity of the battery is reversed. If you connect the battery to a charger or accidentally reverse the polarity while “lighting up” the car, this will most likely cause the motor to burn out. Therefore, you should always remember that plus is connected to plus, and minus is connected to minus.
5. Regular operation of a vehicle with a weak battery. If the battery does not pull the load and constantly operates under conditions of reduced charge, then the reason may be the inoperability of the DM.

Diagnostics

The diagnostic procedure must be carried out on a dismantled generator device, so the unit must first be removed. When the mechanism is dismantled, the plastic cover is removed from it, as mentioned above, the DM is located immediately behind it (the author of the video about self-diagnosis with a multimeter is Ramil Abdullin).

For diagnostics you will need a tester - a multimeter - the test is carried out as follows:

1. First, the multimeter should be activated in ohmmeter mode. Having done this, the positive probe of the tester must be connected to the diode bus.
2. In the same way, connect the negative probe of the tester to the corresponding contact on the diode bridge.
3. Next, you need to monitor the tester readings. If the diode bridge is in working condition, then the tester display will show values ​​close to infinity. If there are no such values, then most likely the DM is inoperative and should be replaced. But the diagnosis does not end there.
4. Next, you will need to swap the location of the probes, that is, the negative contact is connected to the positive one and vice versa. Having done this, again look at the multimeter reading on the display. If there are no failures in the operation of the DM and the device as a whole is functioning normally, then a value of several hundred Ohms should appear on the tester screen.
5. If the DM is equipped with an additional diode, then you can check it too. In this case, the diagnostic procedure is performed in a similar way; you just need to repeat all the steps.

Photo gallery “Self performance test”

Additional testing of generator components faults

The stable operation of this device can be affected not only by the DM and the relay regulator, but also by the electric rotor and stator windings, brushes and capacitor. If the first measurements do not reveal any malfunctions in the operation of the main generator components, then proceed to additional testing of the generator components.

Generator winding testing

This type of measurement is carried out on a dismantled and disassembled generator. You will need to separately check the serviceability of the rotor and stator windings. The meter is set to ohmmeter mode at a value of 200 Ohm.

The main stages of monitoring the electric rotor and stator windings:

1. Measure the resistance value on the rotor windings. For this purpose, probes are connected to the outputs of the windings. The normal value is above 5 ohms, if less than 1.9 ohms, there is a turn short on the rotor. Most often, the electrical circuit breaks in the connection areas between the rotor winding and the ring. It is possible to determine the malfunction by moving the wire in the soldering area with a probe. Alternatively, integrity may be compromised here.
2. Carefully inspect all connections. It is possible that dark and damaged wire insulation will be detected, which is a consequence of a break and short circuit.
3. We call electrical circuits to determine the short circuit on the housing. To do this, the first probe is brought to the rotor shaft, and the second to any ring. If the winding is working properly, the ohmmeter reading will go off scale. If the resistance is low, this winding must be rewound. In this case, perfect balancing must be maintained.
4. Before checking the stator, a visual inspection is performed, paying attention to all kinds of external damage to both the housing and the insulator, as well as the places where the wires from the short circuit are burned.
5. If a defect is detected, the stator is sent for rewinding.
6. If no external abnormalities are found on the stator, examine it with a multimeter.
7. The stator must be disconnected from the generator and removed.
8. The multimeter is set to resistance control mode. Initially, the probes are installed on the 1st pair of terminals. Then they test a pair of windings “1–3”, and then “3–2”. If the analog multimeter needle goes off the scale, the windings will need to be rewinded.
9. To check the generator for the absence of a short circuit between the turns and on the housing. The first probe is connected to the terminal, and the second to the body. If the windings are short-circuited, the multimeter on the scale will show a lower resistance value than on the working ones.

How to check the brushes of a VAZ-2110 generator with a multimeter

The brush apparatus is removed from the generator and an external inspection is carried out. They wear out during operation due to the fact that they are constantly in contact with the commutator plates, as a result of which wear occurs on both parts of the brushes and the commutator. At a time when wear becomes critically dangerous and the action of the spring becomes insufficient to ensure good contact, the process of excitation of the rotor winding deteriorates. Ultimately, wear of the brushes leads to a drop in charging voltage.

Important! The drop in charging voltage occurs gradually, almost imperceptibly for the car owner, and therefore it can appear at the most inopportune time. The process accelerates in severe frosts, a large number of cold starts, and frequent trips over short distances. This will happen until one day the EMF from the battery is insufficient to start the engine and the car will not start. Such difficulties are especially inherent in diesel cars, since the starter of these engine modifications requires even more current.

Upon external inspection of the brushes, they should be evenly worn, while their length should be equal, and the wear from the generator rotor rings should be symmetrical about the longitudinal axis. The residual size of the brushes should be more than 5 mm, with a norm of 8 to 10 mm. If such characteristics are absent, the brushes are changed in any case, even if the generator failure has other sources.

If the length of the brushes is of an acceptable size, then they need to be checked with a multimeter in resistance control mode. The probes are connected according to the diagram indicated below.

Normal brush resistance should be in the range of 0.5–1 Ohm; brushes with higher values ​​are rejected.

How to check the capacitor of a VAZ-2110 generator with a multimeter

A damaged capacitor also leads to malfunctions. It can be checked with a multimeter on a scale of 1–10 MΩ. The multimeter test leads are connected in one direction to the terminals of the capacitor. Before connecting, the meter shows infinity. When connected, the resistance drops, and then rises again to infinity. In this mode, the capacitor is technically operational.

Important! When reassembling the capacitor and brush holder on the generator, they are installed in the reverse order of dismantling. For those car enthusiasts who are doing this for the first time, it is better to take photos and videos of the process of disassembling the generator. When assembling the capacitor, it must be installed exactly along the mounting protrusion on the cover, otherwise the brush holder will not be installed in place.

The diode bridge is a reliable device that is necessary for the smooth operation of the generator. However, it is not protected from moisture, poor machine maintenance and poor contacts, which lead to premature failure. To make sure that it is faulty, experts recommend checking the VAZ-2110 generator with a multimeter. To do this, you will need to remove it from the generator, which will take no more than 10 minutes. The test is carried out with a multimeter. A working DM should conduct current exclusively in one direction. If this is not the case or the multimeter does not show cross-country ability at all, then such a bridge should be replaced with one of the same type for the VAZ-2110.

DIY replacement instructions

In the event of a breakdown, the repair of the DM consists of its replacement, which is done as follows:

1. First you need to turn off the ignition, open the hood and turn off the power to the on-board network; to do this, disconnect the battery.
2. Once the battery terminal is reset, you will need to disconnect the pink cable responsible for activating the generator assembly. The wire itself is fixed with a bolt and nut; the nut itself will need to be unscrewed.
3. Now you need to slightly loosen the tension on the top as well as the bottom nuts. Unscrew the tension screws and remove the strap. Inspect it - if the belt shows signs of damage - cracks, delamination - then it is better to change it immediately. If the strap is intact, set it aside.
4. After completing these steps, you need to rotate the generator mechanism 90 degrees, this is done so that you can access the lower mounting screw. Unscrew it.
5. Next, carefully inspect the body of the dismantled unit. If necessary, clean - there should be no dirt, especially on the connections. Dirt getting inside the generator housing can also lead to its incorrect operation and even failure. Bend the fasteners and remove the cover.
6. Next, you need to clean the inside of the rings as carefully, but most effectively as possible.
7. After this, all you have to do is dismantle the failed DM and replace it with a working part. When the installation is completed, the structure is assembled in the reverse order. Do not forget to tighten the strap, just make sure that it is not too tight, this is important. Having done this, you will need to start the engine of your car and diagnose the operation of the new DM.

Video “How to avoid mistakes when replacing the DM in a VAZ 2110”

More clear instructions for replacing the diode bridge in the “Ten” with a description of the main points and nuances are given in the video below (the author of the video is Semyon Pedan).

Let's start with the fact that a diode bridge is an electrical circuit, a chain of diodes designed to convert alternating current into direct current. A faulty diode bridge is one of the main causes of generator malfunction, and is also a powerful consumer that can drain the battery to zero overnight.

A faulty diode bridge can both discharge and recharge the battery, which can result in major electrical problems. The principle of diodes, in addition to converting current from alternating to direct, is the unipolarity of current transmission from the generator to the battery. In other words, a working diode transmits current only in one direction (generator - battery), a faulty diode transmits current in both directions (battery - generator) or does not transmit anything at all. Diodes burn out due to poor contacts or moisture.

Before you start blaming the diode bridge for all your problems, be sure to check the generator brushes and voltage regulator.

To start checking the diode bridge, you need to remove it, fortunately the process is simple. You can also do without removing the rectifier block (diode bridge), but this is very, very inconvenient.

One way to check the diode bridge is to check the on-board system for current leakage (How to check for current leakage?)! If the current consumption in a stopped engine with electrical appliances turned off is 1A per hour or higher, then most likely the problem lies in the diode bridge. The bridge can only be checked more thoroughly when removed.

Lada 2112 White Bird › Logbook › Gene faults and their elimination (article from the Internet)

Malfunctions of vehicle electrical equipment are very common and occupy one of the leading places in the list of breakdowns. They can be roughly divided into faults of power sources (batteries, generators) and faults of consumers (optics, ignition, climate, etc.). The main sources of power for a vehicle are batteries and generators. The malfunction of each of them leads to a general malfunction of the car and its operation in abnormal modes, or even immobilization of the car.

In the electrical equipment of a car, the battery and generator work in an inextricable tandem. If one fails, after a while the other will also fail. For example, a damaged battery leads to an increase in the charging current of the generator. And this entails a malfunction of the rectifier (diode bridge). In turn, if the voltage regulator supplied from the generator malfunctions, the charging current may increase, which will inevitably lead to systematic recharging of the battery, “boil-off” of the electrolyte and rapid destruction.

Common battery problems:

short circuit of battery electrodes/plates; mechanical or chemical damage to the battery plates; violation of the tightness of battery cans - cracks in the battery case as a result of impacts or improper installation; chemical oxidation of battery terminals. The main causes of these malfunctions are: gross violations of operating rules; expiration of the product's service life; various manufacturing defects. Of course, the design of a generator is more complex than a battery. It is quite reasonable that there are many times more generator malfunctions, and their diagnosis is much more difficult. Common generator problems include:

▶ wear or damage to the pulley; ▶ wear of current collecting brushes; ▶ wear of the commutator (slip rings); ▶ damage to the voltage regulator; ▶ short circuit of the stator winding turns; ▶ wear or destruction of the bearing; ▶ damage to the rectifier (diode bridge); ▶ damage to the charging circuit wires.

It is very desirable for a motorist to know the main causes of generator malfunctions, how to eliminate them, as well as preventive measures to prevent breakdowns.

All generators are divided into alternating and direct current generators. Modern passenger vehicles are equipped with alternating current generators with a built-in diode bridge (rectifier). The latter is necessary to convert current into direct current, on which the vehicle's electrical consumers operate. The rectifier, as a rule, is located in the cover or housing of the generator and is integral with the latter. All electrical appliances of the car are designed for a strictly defined operating voltage range. As a rule, operating voltages are in the range of 13.8–14.7 V. Due to the fact that the generator is “tied” with a belt to the engine crankshaft, it will work differently depending on the speed and speed of the vehicle. It is for smoothing and regulating the output current that the relay-voltage regulator is designed, playing the role of a stabilizer and preventing both surges and dips in the operating voltage. Modern generators are equipped with built-in integrated voltage regulators, colloquially referred to as “chocolate” or “tablet”.

It is already clear that any generator is a rather complex unit, extremely important for any car.