Problems with a car generator always cause disappointment, but also a lot of questions from inexperienced car enthusiasts who do not know how to repair it. If you understand the problem, it will immediately become clear how simple the path to restoring the functionality of such equipment is. Let us now consider the principle of operation, the main malfunctions of the generator and how to eliminate them.
A car generator is needed to convert the mechanical energy of rotation of the crankshaft of a car engine into electrical energy.
Signs of a burnt diode bridge
The battery was fully charged the day before, you came to the garage - there was no charge, you charged the battery again, started the car, the battery was discharged after a few minutes, and the generator was so hot that it was impossible to touch it.
A terrible howl/whistle is heard from under the hood, which changes tone when the engine speed changes; the whistle can appear suddenly while driving.
The headlights dim while driving, the speakers turn off spontaneously, and the air conditioning stops working.
In order to confirm your opinion that it is the diode bridge that has failed, you need to check it. The following factors indicate a malfunction of the diode bridge:
· voltage at the generator output is less than 13.5 V;
· the signal indicator lights up when the engine starts;
· when testing the generator with a multimeter, the plus terminal “rings” along with the windings.
We made sure that the fault lies precisely in the diode bridge. Now we need to find and determine which diode has failed.
Signs of diode failure
The main problem in a rectifier bridge is the diodes. You should start checking the unit that generates electricity in the car only after identifying the following indirect problems:
- the voltage at the generator output terminals is below 13.5 Volts;
- the indicator on the instrument panel inside the car continues to light after starting the power unit;
- the arrow on the voltmeter shifts to the red zone when readings are taken;
- The battery indicator does not light up after turning on the ignition.
Similar symptoms are detected when the voltage regulator breaks down; therefore, its serviceability is checked first. There are various reasons why a rectifier bridge fails, which requires its repair or complete replacement.
Checking the diode - how to do it right
Based on the fact that a diode is a semiconductor device that passes current only in one direction, let’s begin the test.
· The diode bridge must be removed. Diodes need to be checked individually, disconnected from the general circuit. The test must be performed in the “diode check” position.
· We touch the bottom of the diode with one of the probes, and its terminal with the other. The amount of resistance depends on the power of the semiconductor. The resistance should be in the range of 400 - 800 Ohms, that is, the diode passes current in this direction.
· Swap the probes. A unit on the multimeter screen is evidence that there is no conductivity in this direction. This means the diode is locked and intact.
· Otherwise, if the tester shows the presence of resistance (current flow) in both directions during testing, this indicates a diode malfunction.
Important to remember. When checking diodes located on the same plate, the resistance should not differ. The permissible maximum is 5 Ohms, no more. The presence of a diode with a large difference in readings indicates its poor performance and subsequent charging problems. Therefore, it is advisable to change the diode.
Checking diodes with a tester is very conditional; you can more accurately verify the integrity of the diode only under load, for example, by connecting a lamp to the circuit or on a diagnostic test bench at a service station.
DM functions
If we recall the physics course from school, we will conclude that there are two types of electric current. It is constant and variable. How are they different from each other?
There's nothing complicated here. The key difference is that alternating current has charged particles that move in different directions. In the case of direct current, movement always occurs in only one direction.
I would like to note that alternating current has noticeably better economic characteristics. They cope more effectively with transmitting current over fairly long distances. The only problem is that most electrical appliances in vehicles are powered by direct current. In order for a vehicle to function properly, electrically dependent equipment must receive a certain amount of direct current. The generator itself cannot provide it, since it produces alternating current.
Our today's hero allows us to solve this problem. That is, a diode bridge. It looks like a pair of metal conductive plates. They contain diodes that act as semiconductors. They are installed in a certain sequence.
The DM allows current to pass, but the bridge sets one direction. That is, the straightening process occurs. Another nuance is that the bridge sets traffic in only one direction. Namely, from the generator to the on-board network.
The serviceability of the DM is not eternal. Periodically, the generator element fails. And it doesn't matter what kind of car you have. It could be:
- VAZ 2107;
- VAZ 2114;
- Toyota Corolla;
- Lada Priora;
- Nissan Qashqai;
- Daewoo Matiz;
- VAZ 2110;
- Mitsubishi Lancer;
- Ford Mondeo;
- UAZ Patriot;
- Hyundai Solaris, etc.
Regardless of the car, you can and should check the functionality of the device with your own hands. For these purposes, it is important to use a tester.
If you are not sure about the correctness of your actions, watch visual videos. Don’t rush to blame the bridge for everything. Without disassembling or unsoldering the diodes, first make sure that it is faulty.
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
Signs of a diode bridge malfunction
First of all, you need to remember that the diode bridge on the VAZ-2114 is no different from the same unit on the VAZ-2109, VAZ-2110 and other models. Therefore, if you figure out how to determine the malfunction, it will not be difficult to identify it on any of the cars. There are several main symptoms; they can appear together or separately. Any of them requires an immediate check of the generator:
These are the main signs of a diode bridge breakdown, but it is worth remembering that they may indicate other generator failures. Therefore, first of all, you need to accurately identify the faulty unit. It is not necessary to take the car to a service center for diagnostics; the car owner can do the work; a minimum set of tools is needed.
If the control light on the panel lights up or, conversely, does not work, first of all you need to check it and the control relay. Often it is these elements that are faulty, and not the generator.
No charging VAZ 2109
>When driving a car, you should always pay attention to whether the battery is charging. The VAZ 2109 battery is needed only to start the engine
While the engine is running, all electrical appliances of the VAZ 2109 operate from. Naturally, if the generator stops working, the battery doesn’t last long. How can you tell if the battery has stopped charging? There is a standard voltmeter on the instrument panel. According to its readings, it is very clear whether the generator is working or not. When the VAZ 2109 engine is running, the voltmeter should show a voltage of about 13.5 - 14 V. If you notice that the arrow is always tilted to the right, that is, the on-board voltage is less than 12V, then there is no charging from the generator. It is also very convenient to monitor the voltage of the on-board network of the VAZ 2109 using a digital tachometer. It measures the voltage from the generator with an accuracy of tenths of a volt.
Generator VAZ 2109
I recently had the following situation: I was driving and I saw that the voltage on the instrument panel voltmeter was about 11 Volts. Clearly, there's something wrong with the generator. Well, as usual, there is no time to repair it, it’s dark and cold outside, there is no garage. Well, as always, you need to drive a car every day, you can’t do without it. Therefore, at night every day I put the battery on charge, and in the morning I put the fully charged battery in the car and drove. If you drive only during daylight hours, that is, without headlights, then the battery may last for several days. If, as I did, you have to drive to work in the dark in the morning, then in the evening the battery will run out completely. Of course, it all depends on how often you turn off and start the engine. A lot of battery energy is wasted just for rotating the starter, you can also try to drive without it, then the battery is needed only for the operation of the ignition system and light signaling (stops, turns). Until recently, I believed that no matter how dead the battery was, the VAZ 2109 could always be started from the pushrod. It turned out that this was not true. There is a certain degree of discharge when the starter no longer has enough strength to turn the crankshaft, but it is enough. I pushed it, put it in gear, started up and everything was fine. However, if the battery is completely dead, it does not even have enough power to form a spark. , don’t push, the VAZ 2109 won’t start until you recharge the battery. But still, what to do if the VAZ 2109 battery has lost charging? Of course, not every one of us is an electrician and can check the generator with all its diodes, stabilizers and collectors. The very first thing to do if the VAZ 2109 generator stops working is to check the generator brushes. It’s easy to understand that the VAZ 2109’s brushes are faulty or worn out. Turn on the ignition and look at the instrument panel.
Checking the serviceability of the VAZ 2109 generator brushes
If the brushes are faulty, then the battery charging lamp will not light up when the engine is not running. Or it will glow very dimly. After you start the engine, the light will continue to glow dimly. The dim glow is visible only in the dark; it cannot be seen during daylight hours. If the brushes are in good working order, then when the engine is not running, the battery charging lamp lights up brightly; if it is started, it immediately goes out. It should be noted right away that the VAZ 2109 produced before 1993 has old-style brushes. On the new VAZ 2109, brushes of a new type are installed, immediately with a voltage stabilizer. However, there are both new and old samples of VAZ 2109 brushes on sale. The cost of VAZ 2109 generator brushes is about $3-5. Replacing the VAZ 2109 generator brushes is very simple, the sequence is as follows: 1. Remove the ground from the battery
Removing the mass of the VAZ 2109
2. Disconnect the chip from the generator brush housing and remove the wires from the central stud of the generator.
Disconnect the wires from the VAZ 2109 generator
Wires pulled back
3. Now unscrew the two bolts securing the brushes to the VAZ 2109 generator housing. And slowly remove the brushes from the generator housing.
We unscrew the bolts securing the generator brushes of the VAZ 2109
4. If you want the new brushes to last a long time, you need to clean the generator commutator. To do this, loosen the nut on the generator mounting bracket, loosen the belt and remove it. We take fine sandpaper, press it against the commutator, and we ourselves rotate the generator using the drive wheel. In this way, graphite deposits from previous brushes are removed from the commutator. And the wear of the new brushes will be long. 5. Now we insert new brushes into the housing of the VAZ 2109 generator and clamp them.
Generator brushes VAZ 2109
6. We put back all the chips and wires of the VAZ 2109 generator.
VAZ 2109 generator brushes replaced
We check the functionality of the generator as indicated above.
Diagnostic methods
There are two main methods that will allow you to determine the malfunction of the generator diode bridge. You need to choose based on what you have at hand. The first option requires the presence of a multimeter, and the most entry-level option, which is inexpensive, is suitable. The second is a regular 12V light bulb with three long wires so you can connect them to the right pins.
Diagnostics using a multimeter
Let's look at the option without removing the diode bridge, since it requires less time. The test is easy to carry out on an installed unit if you know the main features. The process is simple; you first need to provide access to the generator contacts. After this, carry out the following checks:
Do not forget to first switch the device to ohmmeter mode.
Using simple recommendations, you can literally check in a few minutes and find out whether the diode bridge has burned out or the reason lies in another unit. You can use not only a multimeter, but also any other device if it has an ohmmeter mode.
Checking the bridge with a light bulb
This option is especially good on the road, because it only requires a 12-volt light bulb and three long wires with bare ends. Or you can use a ready-made warning lamp, they are sold in car dealerships. In this case, proceed like this:
This option, due to its simplicity, allows for quick diagnosis. However, it will not require much time and will allow you to identify the problem within a few minutes. But it is better to work with an assistant to hold the wires.
Why does the diode bridge burn out?
There are several reasons for the failure of the diode bridge on VAZ cars. To prevent the breakdown from occurring again, you need to check the machine for one of the options described below. Only by eliminating the problem can normal operation be ensured.
Most often, a bridge burns down due to the following:
The diode bridge, like any spare part, has its own service life. It usually lasts about 10 years, after which the unit may fail due to normal wear and tear.
It is best to periodically diagnose the car, check the serviceability of the main components and conduct an inspection to identify problems when they are not yet fatal. It is recommended to check the battery annually and measure the charge level to monitor the condition of the generator.
Replacing the Lada Kalina generator
The article provides general information about Lada Kalina generators and explains how to replace the regulator relay and the entire generator itself.
The generator must always be in good working order
Any modern car is equipped with electrical equipment that is absolutely necessary for the vehicle:
- without a starter it is impossible to start the engine;
- a car cannot be driven without lighting at night;
- The heater motor creates heat in the cabin;
- The wiper motor clears the windshield of rain and snow;
- FM radio makes it possible for the driver not to get bored on the road.
But all these devices cannot work without electricity, so the car must have a power source.
The current from which all consumers in the car are powered is produced by the generator, and the performance of the entire electrical circuit of the vehicle depends on its condition.
Therefore, the generator must always be in good working order, and if any breakdowns occur with it, they must be eliminated in a short time.
Generator Lada Kalina
Lada Kalina cars are equipped with three-phase generators that produce alternating current; to produce direct current, a rectifier unit is included in the generator circuit.
AvtoVAZ equips VAZ 1118 cars with generators of the type 5132.3771
or9402.3701-06
, there are many different manufacturers producing spare parts for VAZ cars.
The generator for the Lada Kalina can be of different power; the industry produces current sources of 85, 100, 90, 115, 120, 135 Amperes.
Among the most famous manufacturers of VAZ parts are:
- Pramo;
- StartVOLT;
- KZATE;
- LKD (China);
- Eldix (Bulgaria);
- ISKRA (Slovenia);
- BATE (Belarus);
- Bosch.
Trouble-shooting
There are two main options for solving the problem. The first is accurate diagnostics on the bench: after detecting signs of burnt-out diodes, a check is carried out and it is determined which elements have failed. After this, the faulty diodes are soldered off, and new ones are soldered in their place. It is very important to take exactly the same brand; any analogues will not last long.
It is much easier to change the assembly, it is faster and of better quality, since you can be sure that the spare part will last for some time. The price of the part is low, for example, on a VAZ 2110 it is about 650 rubles. Replacement is not difficult and can be done independently.
Identifying a faulty diode bridge and replacing it is not difficult for any car enthusiast with a minimum set of tools. If the check shows a breakdown, it is best to remove the generator and carry out repairs. The process is simple and takes no more than an hour.
Source
Device
The Lada Kalina generator consists of the following parts:
- housing (front and back cover);
- pulley;
- stator windings;
- armatures (rotor);
- voltage regulator relay (charging relay);
- diode bridge (rectifier unit);
- two armature bearings;
- rear plastic casing.
Inside the generator housing, along its walls there is a stator with a winding, and a rotor is located in the center.
At the back of the case there is a diode bridge and a voltage regulator relay; the diode bridge is covered with a plastic casing to prevent dirt and dust from entering.
There is a pulley in front of the housing; it is put on the rotor shaft and secured with a nut.
The generator is driven by a drive belt placed on a pulley.
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.
