The instrument panels of classic cars of domestic production are not very informative. There is nothing superfluous on them, except for the performance indicators of the main engine systems, but they are quite enough for the driver to be informed on time about possible machine malfunctions. However, it happens that some device fails, and then it is already impossible to determine the breakdown at its initial stage.
In this article we will talk about the case when the battery charging lamp is constantly on, using the example of the popular classic VAZ 2106 and 2107 cars. We will consider the main causes of this phenomenon, and also try to diagnose and eliminate possible malfunctions.
Why do I need a battery warning light?
In order for the driver to be able to monitor the state of charge of the battery, a voltmeter with a scale, as well as a small red window under which a signal light is installed, is located on the instrument panel. When we insert the ignition key and turn it in the lock one turn, this lamp turns on and lights up in red. The voltmeter needle is in the zero position. This means that the generator is at rest and does not charge the battery. When the engine starts, the lamp should go out, and the arrow of the device deviate to the right, showing the amount of voltage supplied to the battery. This happens when the power supply system of the machine is fully operational. But if the VAZ 2107 or 2106 battery charging lamp is on and after the engine starts, most likely, a failure has occurred somewhere. And our task with you is to find its cause and eliminate it.
What the constantly burning battery charging lamp may indicate
If the battery charging lamp is lit in the VAZ 2107 or VAZ 2106 , there can only be one reason - the voltage from the generator is not supplied to the battery, or it is supplied, but its value is insufficient. There can be several malfunctions that lead to this:
- violation of normal contact on the battery terminals;
- loose tension or damage to the alternator belt;
- lack of contact of its "negative" output with the "mass";
- open circuit in the rotor excitation circuit or wear of the generator brushes;
- malfunction of the diode bridge.
- malfunction of the corresponding fuse;
- breakdown of the relay regulator.
Before starting the diagnosis
An important point in solving the question of why the VAZ 2107 or 2106 battery charging light is on is the fact that the voltage from the generator comes to the battery. In other words, if it does not enter the battery at all, there is nothing to be surprised at. The lamp must burn in a similar situation. But if the battery charging light is on, but there is charging, solving this problem will be a little more difficult.
Our first priority is to determine if voltage is being supplied to the battery. To do this is not at all difficult, especially since for this you will need only one device - a voltmeter or multimeter included in its mode. We start the car engine, raise the hood and measure the voltage at the battery terminals with the generator running. If all elements of the system are serviceable, the voltmeter should output 13.6-14.2 V, and no less. This is a working indicator for normal battery charging. If the voltage is below these values, then there is some kind of malfunction.
Disruption of contact at the battery terminals
At this stage of the diagnosis, you need to check the condition of the terminals of the wires and the battery terminals. Often they are oxidized, as a result of which the contact between them weakens. In the case when the battery light is on, but there is charging, it is this malfunction that is most often the cause.
The generator operates in normal mode, voltage is supplied to the terminals, but is lost due to poor contact. So it turns out that charging is in progress, but the battery charging light is on. And it burns in most cases with a dim light. Such a malfunction is eliminated by stripping the terminals and contact terminals of the battery, as well as treating them with water-repellent liquid.
Loose tension or damage to the alternator belt
During the diagnosis, it is necessary to check the condition of the alternator belt. Sometimes it happens that due to its long operation or under the influence of other factors, it is deformed, as a result of which the generator drive gives passes. Pay attention to the belt tension. Its weakening leads to the same effect.
If the belt is not deformed and has no visible damage, you can simply tighten it. Otherwise, it must be replaced. A belt tension is considered normal when it can be turned around the horizontal axis by 85-90 degrees.
The lack of contact of the output of the generator with the "mass"
This malfunction, like the first in our list, occurs due to the oxidation of the terminals and terminals. In addition, disturbance of contact is possible due to the weakening of their fastening. The solution to this problem is to clean the terminals and terminals, as well as treat them with a liquid such as VD-40.
Generator malfunctions
In the case when the battery charging light is on, but there is a charge (VAZ 2106, 2107), the generator must be checked. His most common problems in the context of our malfunction are a break in the rotor excitation circuit or wear (damage) of the brushes.
First of all, the generator must be dismantled and disassembled. To check the rotor winding, we use the same multimeter, included in the ohmmeter mode. We connect its probes to the terminals of the winding and measure its resistance. A working rotor should not be less than 4.5 ohms. If the resistance does not reach this value, most likely, an interturn circuit has occurred somewhere. In the case when it is not determined at all, a break in the winding is possible.
Go to the brushes. We take them out of the seats and inspect for wear. If the length of the brushes does not exceed 7 millimeters or there are traces of damage on them, replace them. Pay attention also to the condition of the brush manifold. If defects in its copper plates are detected, we change the rotor.
Diode bridge
The diode bridge is used to convert AC voltage to DC. In the event of a breakdown of at least one of the diodes, the device ceases to cope with its tasks, which is why a voltage that does not match its parameters begins to flow into the on-board circuit of the machine. That is why the rectifying bridge must be checked if the battery charging light is on, but there is charging (VAZ 2107, 2106).
You can also determine the health of the diodes using a multimeter in the corresponding mode. We turn on the tester and connect the red probe to the positive terminal of the bridge, and the black one to one of the contacts marked “AC”. The threshold (pass) voltage for silicon diodes is from 400 to 1000 mV. If the device shows you a value that does not fit into the specified frames, the bridge must be replaced. It is impossible to repair it.
Fuse Fault
The battery charging circuit, like any other, is fused. It is located in the mounting block under the hood of the car. In “sixes” and “sevens” this fuse is usually designated as F10, but, in any case, it is better to look through the user manual before checking. Most often, when it malfunctions, the voltage to the battery does not come at all, but it also happens that it becomes the reason that the battery charging light is on, but there is charging.
The fuse is checked by the tester after it has been removed from the seat. If the device shows that the part has become unusable, simply replace it.
Regulator malfunction
Another reason that the battery charging light is on, but there is charging, there may be a failure of the relay regulator. It, in fact, is responsible for the timely on-off of this lamp. In VAZ 2106, 2107 cars, the relay is installed in the engine compartment on the top of the wheel mudguard on the right side. The principle of his work is as follows. When the ignition is turned on (with the engine turned off), current flowing from the battery flows through its closed contacts and feeds the test lamp.
When we start the motor, the generator turns on, supplying the relay with an already rectified voltage. Under the influence of it, the device armature is attracted to the core, breaking the contacts. The lamp should go out.
It is not difficult to check the relay yourself. To do this, it is enough to disconnect both wires from it and close them together. We start the engine and look at the warning light. If it is not lit, replace the relay.
Some useful tips
Use the following tips to avoid problems with a malfunctioning battery charging circuit.
- Pay more attention to the car dashboard. So you will know not only about the state of charging the battery, but also about the work of other systems and mechanisms.
- Systematically check the alternator belt. The correct operation of the entire on-board network with the engine running depends on its condition and tension. Having found the slightest defect in the belt, do not pull with its replacement.
- Do not be lazy at least once a month to check the voltage supplied by the generator to the battery terminals. In case of discrepancies with the recommended indicators, conduct a complete on-board network diagnosis.
- Periodically conduct a visual inspection of the status of the battery terminals and generator terminals. Having discovered their oxidation, strip them with a fine sandpaper and treat them with a liquid like VD-40.
- Do not allow water to enter the generator, battery or the relay-regulator. It can cause a short circuit in the electrical circuit. It is better to charge the engine wash to specialists.
- When repairing the battery charging circuit, avoid using parts that are in doubt about quality.