Battery charging light burns

When the engine starts on the dashboard, the set of all light bulbs lights up, one of them is a battery charging light bulb. Ideally, she lights up as soon as you start the engine, and goes out after a while.

This suggests that the generator and all of his chains are fully working and the battery comes with a voltage of 13.7-14.3 volts, that is, it is charging.

However, there are often various breakdowns due to which the light bulb continues to glow, burns dim, or does not burn at all.

To deal with such faults, you need to figure out a little with the device of the generator and the principle of its interaction with the rechargeable battery.

A bit of theory

On our site we have already described the device of the automotive generator in detail. Let's just say that electricity is produced in it due to the rotation of the crankshaft.

With increasing revolutions, the magnitude of the voltage also increases, but it must be in the above limits, otherwise the acb will be reloaded, which threatens the electrolyte boiling and sulfate.

So that this does not occur in the rotor excitation circuit, a regulator relay is installed, thanks to which a stable voltage comes to the battery.

The signal from the generator on the signal lamp is transmitted through the fuse, which is also in the generator itself. Accordingly, the bulb is on until the generator starts to work and transmit voltage to the battery.

The charge with the generator passes through:

• Diode;
• Regulator;
• Generator brush;
• Contact rings;
• Winding and wiring.

Thus, if at least one of these elements does not work correctly or fails, the light bulb readings can not be trusted, although the charging can be supplied to the battery.

Why burn battery charging light bulb?

There may be a lot of reasons. So, if after starting the motor, the warning lamp continues to burn in the full-on, most likely the generator belt stretched and need to be replaced. At the same time, you can hear the characteristic sounds of the engine.

The second common cause is a weak contact on the terminals of the battery or on the outputs from the generator. Contacts over time are oxidized and need to be cleaned.

The breakdown in the mechanical part of the rotor: the bearing was crumbled, "flew" sleeve. We'll have to completely remove the generator, disassemble it and change the broken parts. Fortunately, on sale you can always find a remkomplekt of three sleeves on VAZ-2107 or other domestic cars.

Diode bridge breakdowns, relay controller. In this case, you must check them with a multimeter, or contact the specialists. Often, repairs are more expensive than buying a new generator.

Over time, graphite brushes are also erased, they must be changed regularly. When they wear out, the charge is not transmitted to the winding, respectively, the light begins to glow dimly, although the charge is transmitted, but very weak.

Focus on the voltmeter. If the brushes do not change on time, the battery will be constantly dissimilar, which is fraught with gradual sinking of the plates.

Generator diagnostics

First of all, the tension is measured on the terminals of the AKB.

If it is lower than required, you need to check the entire chain step by step:

• Belt tension level;
• Measure the voltage on each of the generator conclusions - on each of the terminals it should be twice as well as on the battery;
• Check fuses, relays, diodes;
• Check the resistance in the dashboard, the quality of the soldering of the wires.

If it turns out that the breakdown lies in the generator itself, it will have to be removed and also to check. In particular, the relay-regulator first check the relay, then the resistance of the rotor excitation winding is measured using an ohmmeter. It should not be below 4.5 ohms. Also, with the help of the tester, you can determine the rupture of the winding chain.

It is clear that such faults will not be avoided.

However, there are simple tips to help extend the life of the generator:

• First of all, regularly check the quality of its attachment - constant vibrations lead to mechanical damage;
• From time to time, clean the outer surfaces;
• Check the belt tension, pull up if necessary;
• Rotor bearing quality - remove the belt and scroll through the rotor, it should rotate smoothly, without a backlash and click.

You also need to control the quality of the wire connection with the generator and the voltage regulator.

Thus, the burning battery charging light with an engine running is a serious reason for diagnosis. Please note that it can burn and in cases where you have installed a lot of additional equipment - subwoofers, backlight, lights.