Everything about a car generator - device, operating principle

Author: Ivan Baranov

As with any car, the generator on the VAZ 2107 injector works in parallel with the battery - these are two power sources for the car, which are used in different modes. The article discusses the generator 37.3701, the principle of operation of the generator with different characteristics, including a maximum current of 80 Amperes, and provides instructions for connecting the unit. The G222 generator set is similar, you just need to pay attention to some differences.

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Generator VAZ 2107: purpose and main functions

As with any other car, the generator on the “seven” works in tandem with a battery. That is, these are two power sources in the car, each of which is used in its own modes. And if the main task of the battery is to maintain the functionality of electronic devices during the period when the engine is turned off, then the generator, on the contrary, produces current only when the engine is running.

The main task of the generator set is to generate electrical energy by charging the battery. That is, in many ways (if not all) the performance of the machine depends on how well the generator and battery work.

Generator sets for the VAZ 2107 have been produced since 1982. Their factory marking is G-221A.

All VAZ classic cars, including model 2107, were equipped with G-221A generators

Technical characteristics of the generator G-221A

The VAZ 2107 was equipped with two types of generators (carburetor and injection), each of which had its own factory marking: 372.3701 or 9412.3701. Therefore, the operating characteristics of the devices may differ, since injection models consume more electricity, and accordingly, the generator power must be higher.

All VAZ 2107 generators have the same rated voltage - 14 V.

The generator for a carburetor car has modification 372.3701 and is made in an aluminum cast housing with steel fasteners

Table: comparison of characteristics of different modifications of generators for VAZ 2107

What generators can be installed on the “seven”

The design of the VAZ 2107 allows the installation of not only the G-221A generator. Therefore, if necessary, the driver can install a more powerful device, however, this will require making some changes to the electrical circuit of the car. The question arises: what is the reason for the desire of a car enthusiast to change his “native” generator?

The G-221A was the optimal device for equipping cars at the beginning of their mass production. However, a lot of time has passed since the 1980s and today almost every driver uses modern electronic devices:

• acoustic system;
• navigators;
• additional lighting devices (tuning), etc.

  
  Non-standard lighting devices consume the most electricity

Accordingly, the G-221A generator cannot cope with high loads, which is why drivers begin to look for more powerful units.

You can install at least three more powerful devices on the “seven”:

• G-222 (generator from Lada Niva);
• G-2108 (generator from the G8);
• G-2107–3701010 (injection model for a carburetor car).

It is important that the last two models do not require changes in the design of either the generator housing or its mountings. When installing a generator from Niva, you will have to make some modifications.

Video: principle of operation of the generator

Connection diagram G-221A

Being an electronic device, the generator needs to be used correctly. Therefore, its connection diagram should not cause ambiguity. It should be noted that drivers of “sevens” can usually easily connect all the generator terminals themselves, since the circuit is accessible and understandable to everyone.

The generator (item 2) is connected to the circuit in series between the battery (item 1) and the mounting block (item 3)

Many car owners wonder where which wire should be connected when replacing the generator. The fact is that the device has several connectors and wires, and when replacing, you can easily forget which wire goes where:

• orange is not useful for connection, it can be left as is or connected to gray directly to autostart the car;
• a gray thick wire goes to the brushes from the relay regulator;
• a gray thin wire connects to the relay;
• yellow - coordinator of the control light on the control panel.

When working independently with the G-221A, it is better to sign the purpose of the wires so as not to connect them by mistake later.

To avoid errors, all wires have their own color designation

The device of the VAZ 2107 generator

Structurally, the generator on the “seven” has the shape of a cylinder. The cast body contains many small parts, each of which performs its own functions. The main elements of the G-221A are the rotor, stator and covers, which are cast only from a special aluminum alloy.

Rotor

The G-221A rotor consists of a shaft with a corrugated surface, onto which a steel sleeve and poles are pressed. The bushing and beak-shaped poles together form the so-called core of the electromagnet. The core produces an electromagnetic field during the rotation of the rotor shaft.

The excitation winding is also located inside the rotor. It is placed between the poles.

The moving element of the rotor - the grooved shaft - rotates thanks to two ball bearings . The rear bearing is mounted directly on the shaft, and the front bearing is fixed on the generator cover.

The rotor is pressed into the generator winding and does not separate from it during disassembly

Stator

The stator is assembled from special plates 1 mm thick. The plates are made of electrical steel. It is in the stator slots that the three-phase winding is located. The winding coils (there are six in total) are made of copper wire. Strictly speaking, the electromagnetic field coming from the rotor core is converted by the coils into pure electricity.

Wire breaks or carbon deposits on its surface can affect current generation

Rectifier

The generator in the described configuration produces only alternating current, which is clearly not enough for the smooth operation of the car. Therefore, in the G-221A case there is a rectifier (or diode bridge), the main task of which is to convert alternating current into direct current.

The diode bridge has the shape of a horseshoe (for which it received the corresponding nickname among car enthusiasts) and is assembled from six silicon diodes. On the plate, three diodes have a positive charge and three have a negative charge. A contact bolt is installed in the center of the rectifier.

Structurally, the rectifier really looks like a horse's horseshoe

Voltage regulator

The voltage regulator on the VAZ 2107 is made together with a brush holder. The device is a non-separable unit and is fixed to the back cover of the generator. The regulator is designed to maintain the rated voltage in the network in any operating mode of the engine.

The regulator's electrical circuit controls the voltage in the device

Pulley

The pulley is not always considered an integral part of the generator, since it is mounted separately on an already assembled housing. The main task of a pulley is to transmit mechanical energy. As part of the generator, it is connected by a belt drive to the crankshaft and pump pulleys. Therefore, all three devices work in an inextricable connection with each other.

The pulley is mounted on the rotor shaft and connected by a belt drive to the corresponding parts of the pump and crankshaft

Main details

To understand where to look, you need to remember the main components that make up the generator. This:

• pulley;
• front bearing;
• rotor impeller;
• stator winding;
• magnetic circuit;
• rotor;
• rear bearing;
• “chocolate” (relay-regulator);
• diode bridge.

Most often, the brushes that are part of the relay-regulator unit wear out. Bearing wear is also common. You should also expect breakdowns of the diode bridge and the generator belt (which drives the pulley). Another part that requires periodic replacement is slip rings. They are located on the rotor and are in contact with the brushes.

To increase service life, you should regularly lubricate the mechanical components of the device (especially bearings), measure the voltage, the battery charge level and its condition, and tighten the fasteners. If you suspect any kind of breakdown, you must immediately begin repairs, otherwise there is a risk of failure of any connected device and component. If an injector and an ECU are installed on the car, then they do not joke with electricity. And the most ordinary care and prevention will reduce the likelihood of breakdown to almost nothing.

Generator faults

Unfortunately, mechanisms have not yet been invented that would not fail under the influence of time and constant loads. The VAZ 2107 generator is designed for many years of operation, but in some cases this is hampered by minor breakdowns and malfunctions of its components.

You can identify problems with the generator without the help of service station specialists: you just need to carefully monitor all the changes that occur with the car while driving.

The charging indicator light on the instrument panel came on

In the interior of the VAZ 2107, there is a terminal for several signaling devices on the dashboard. One of them is the battery charging indicator light. If it suddenly lights up red, it means there is not enough charge in the battery or there is a problem with the generator. But the alarm does not always indicate a problem with the generator itself; most often the lamp goes off for other reasons:

• slipping of the generator belt drive - you will need to stop the machine and adjust the degree of belt tension;
• there is damage in the warning lamp relay, so it does not work correctly - it is recommended to “ring” the relay in the mounting block and, if necessary, replace it;
• breakage of contacts in the excitation winding is a more serious damage that requires removing the generator from the car, disassembling it and searching for a break;
• severe wear of the brushes in the brush holder - they will need to be replaced, which is quite simple;
• short circuit in the rectifier (most likely, one of the silicon diodes has burned out) - it is recommended to disassemble the generator, test the diodes and replace the failed element.

The driver will immediately notice the signal, as the lamp begins to glow bright red on the instrument panel

The battery is not charging

VAZ 2107 drivers often encounter this problem: the generator seems to be working properly, but there is no power to the battery. The problem may lie in the following malfunctions:

• the alternator belt has stretched - you need to check the degree of its tension or replace it with a new one;
• loosening the fastening of the wire tips - just tighten all the fastening connections and thoroughly clean the contacts and connectors;
• malfunction of the battery itself;
• Damage in the wiring - it is recommended to ring all the wires between the battery and the generator and replace the damaged areas.

If there is no charging, the problem may lie in both the generator and the battery.

The battery is boiling over

Battery boiling over is a sign that the battery does not have long life left. After this, the battery will not be able to function fully, so it will have to be replaced soon. However, so that the replacement does not lead to the same sad consequences, it is necessary to find the cause of the boiling, which may be:

• contamination of the contact between the ground and the housing of the generator regulator - cleaning of the contact is necessary;
• damage to the voltage regulator board itself - replacement of the board is recommended;
• defective battery - if the battery began to boil away immediately after replacement.

It is better not to use the battery after boiling, as its resource is very limited.

When driving there is noise and grinding noise from the generator

The generator has a rotating rotor, so it must make noise during operation. However, if these sounds become increasingly loud and unnatural, you should understand the cause of their occurrence:

• loosening the nut on the pulley - you need to tighten the nut and check the degree of belt tension;
• deterioration of the bearings - in this case, the driver may hear a loud grinding noise and even a howl while driving; it will be necessary to press out the old bearings from the shaft and install new ones;
• short circuit in the winding - the entire stator needs to be replaced;
• creaking brushes - it is recommended to clean the brushes from adhering dirt.

Trouble-shooting

The warning lamp and sensor (on-board voltmeter) show the presence of a charge, and the battery is flat, but checking with a multimeter shows a normal voltage of 13.6-14.2 V at the battery terminals. When a large load is turned on (for example, high beam headlights), the gauge arrow turns white scale sector.

The cause may also be a breakdown of one of the negative diodes, a burnout of one of the positive diodes of the rectifier, or a break in one of the stator phase windings. When the engine is not running, the negative diodes are checked: the “+” terminal of the battery is disconnected from the vehicle network and a test lamp is connected to it. Use the lamp leg to touch each of the three bolts securing the generator rectifier unit. If the lamp is on, the negative diode connected to the bolt is broken.

To check the positive diodes, connect the “+” terminal and disconnect the “-” terminal from the body, to which the test lamp is connected. Again, use the lamp leg to touch each of the three bolts securing the generator rectifier unit. Burning of the lamp also means breakdown of the positive diode. If you have a multimeter, simply measure the resistance of the diodes in the polarity in which the diode should be locked: for negative diodes “+” to the bolts, and “-” to the body, for positive diodes “+” to terminal “30” of the generator, and “ -" - to the bolts. A diode rectifier with a broken diode is completely replaced.

The break of one of the branches of the stator winding is checked by ringing them with a multimeter or a “tester” with a battery between the two bolts of the rectifier unit. The absence of contact of any winding with each of the two remaining ones indicates its breakage, and the generator must be repaired or replaced.

Check the generator brushes

Another reason could be wear on the generator brushes. The brush assembly from the PP is removed. If the brushes are less than 5 mm long, the unit is replaced with a new one. If the brushes are not worn out, they should be inspected for the possibility of distortion and “sticking” in the housing wells.

The charge lamp does not light up when the ignition is turned on. The charge sensor and other control devices do not work. The generator did not charge.

The cause of this malfunction is that fuse F10 (10 A) has blown. If nothing has changed after replacement, look for the reasons in the ignition lock or relay (if installed).

When the ignition is turned on, the control lamp does not light up. The charge sensor and other control devices are working. The generator does not charge.

The wire is disconnected from plug “61” of the generator and shorted to ground. If the lamp is on when the ignition is on, the generator excitation winding is faulty or there is no contact in the plug itself. The surfaces of the pins are cleaned, the bends of the plug connectors are pressed, and connected. It is checked again and if the charge lamp does not light up again, the plugs Ш5-Ш10 of the mounting block and the pins in the connector of the block with the instrument panel are cleaned. If there is no result, then the lamp itself has burned out. To replace a light bulb, the instrument panel is removed, the socket is removed from behind the panel, and the lamp is changed.

The battery light comes on when the ignition is turned on. When the engine is idling, the charge lamp lights up dimly, charging disappears or there is no charging at all.

The reason may be poor contact of the pin of the wire connection block to the instrument panel. It is attached with a rivet and often oxidizes. If you solder it to the board track, this problem is eliminated. Also, loose contact at the connection points along the wire path from the shield to plug “61” of the generator gives the same symptoms.

To check the excitation winding for an open circuit, use a multimeter probe to touch the rotor rings with the brush assembly removed - the working winding shows a slight resistance. When one probe touches the ring and the other touches the shaft or rotor housing, check for a winding short to ground. To check the voltage regulator relay, connect the “+” battery to the top contact, and “-” to the left one, and measure the voltage on the brushes. It should be 12 V. If not, the relay must be replaced.

Generator check

Problems with the generator set can be avoided if the condition of this unit is periodically diagnosed. Checking the functionality of the generator gives the driver confidence that it is working properly and there is no cause for concern.

You cannot test the generator by disconnecting it from the battery while the engine is running. This is fraught with power surges and short circuits . The easiest way is to contact a service station specialist to check the functionality of the generator on a stand. However, convinced “seven guides” have long adapted to checking the G-221A on their own using a multimeter.

For diagnostics, you will need a multimeter of any type - digital or indicator. The only condition: the device must work correctly in both AC and DC measurement modes.

Operating procedure

Two people will be required to diagnose the generator's functionality. One of them should be in the cabin and, upon a signal, start the engine, the second should directly monitor the multimeter readings in different modes. The operating procedure will be as follows.

1. Switch the device to constant current mode.
2. With the engine turned off, connect the multimeter first to one terminal of the battery, then to the second. The network voltage should not be less than 11.9 and more than 12.6 V.
3. After the initial measurement, start the engine.
4. When starting the engine, the measurer must carefully monitor the instrument readings. If the voltage drops sharply and does not rise to operating condition, this indicates the exhaustion of the generator's life. If, on the contrary, the voltage indicator is higher than normal, then the battery will soon boil away. The best option is that when you start the engine, the voltage drops slightly and immediately recovers.

   
   If the voltage measured with the engine running is between 11.9 and 12.6 V, then the generator is ok

Video: procedure for checking a generator with a light bulb

Generator set belt for VAZ 2107

The VAZ 2107 car was produced from 1982 to 2012. Initially, the model was equipped with a smooth drive belt (old model). Over time, the “seven” was modified several times and at the end of the 1990s, the generator began to work with a new type of belt with teeth.

The most popular among car owners are rubber products from the German company. These belts fit perfectly into the operation of a domestic car and serve for the entire period specified by the manufacturer.

The operation of the generator and the entire vehicle depends on the quality of the drive belt.

The design numbers and sizes of the belts are indicated in the vehicle’s service book:

• 2101–1308020 (smooth surface), dimensions - 10.0x8.0x944.0 mm;
• 2107–1308020 (toothed surface), dimensions - 10.7x8.0x944.0 mm.

How to tension a belt on a generator

The operation of the generator, as well as the water pump, primarily depends on the correct tension of the belt on the pulley. Therefore, existing rules cannot be neglected. The belt is installed and tensioned in the following order.

1. Place the assembled generator in place, lightly tightening the fixing nuts.
2. Take a pry bar and use it to fix the gap between the generator housing and the pump.
3. Place the belt on the pulley.
4. Without releasing pressure from the pry bar, pull the belt onto the pulley.
5. Tighten the top nut securing the generator until it stops.
6. Check the degree of belt tension - the rubber should not sag, but it should not be too tight.
7. Tighten the lower nut securing the generator.

   
   A well-tensioned drive belt should give slight deflection when pressed, but not be excessively loose.

Video: how to tighten the alternator belt

Checking the degree of tension is done with two fingers. You need to press the free part of the belt and measure its deflection. The optimal deflection is 1–1.5 centimeters.

Thus, we can say that independent maintenance of the generator on a VAZ 2107 is quite possible and does not fall into the category of impossible tasks. It is important to follow the recommendations and algorithms for this or that work in order to carry out quality repairs or diagnostics. However, if you have doubts about your skills and abilities, you can always turn to professionals for help.

How to replace the charging relay?

If after taking these measures there is no effect, you need to look for the cause in the generator, we’ll talk about this next time. At the same time, remember that if you are removing a generator, then either you have decent knowledge in electrical engineering, or you have someone to give it to. There is no third option, especially if you have an injector.

In conclusion, let me tell you about several other reasons for the lack of charging or imitation, and also give advice:

If you suddenly notice that your VAZ 2107 car has lost charging, this problem must be corrected immediately. If you operate the car without charging, the battery will run out very quickly and you will have to use a tow truck or tow truck.

To find the reason for the battery not charging and how to fix this problem, you need to start with theory.