The battery discharges while the car is parked
1. The anti-theft alarm system consumes a lot of current. With a multimeter (ammeter) measure the current consumption. Repair or replace the anti-theft alarm system.
2. Current leaks in the vehicle's electrical equipment. With a multimeter (in ammeter mode) measure leakage current. Disconnecting the car's circuits one by one (removing fuses), we determine the faulty circuit with the highest leakage current. We replace the faulty part or eliminate the short circuit in the power supply circuit of the electrical equipment (see "Electrical equipment - technical condition check").
The battery is not charging (the battery charge indicator light does not go out after starting the engine)
1. The drive belt is not sufficiently tensioned or is worn out. Check the condition and replace the accessory drive belt if necessary (see "Auxiliary Drive Belts - Replacement").
2. Low electrolyte level in the battery. Check the condition of the battery (see "Battery"). In a low-maintenance battery, bring the electrolyte level to normal and charge. Replace the maintenance-free battery.
3. The terminals on the battery terminals are not tightened sufficiently or are oxidized. Clean the wire terminals and battery terminals from oxidation (see "Battery - Maintenance"). After connecting the terminals, cover them and the battery terminals with a special compound or any plastic lubricant.
4. The generator is faulty. Check the technical condition of the generator (see "Generator - check"). Repair or replace the faulty generator.
5. The voltage regulator is faulty. Check the technical condition of the generator (see "Generator - check"). Replace the faulty voltage regulator or generator assembly.
6. The electrical circuit for charging the battery is faulty. Check and repair the electrical circuit (see "Electrical equipment - technical condition check").