The generator is the power plant of your car. When the engine is running, it supplies all electrical units with current and charges the battery

In a car, depending on the engine model and equipment, an alternating current generator operates.

Additional units determine whether the generator is driven by a V-belt or a V-ribbed belt.

Since the battery must be charged with direct current, semiconductor diodes take care of rectifying the alternating current.

These diodes are very sensitive to high voltage. The faster the generator rotor rotates, the higher the voltage rises.

The current consumers in a car will not withstand such ups and downs for long.

Therefore, there is a voltage regulator that limits the voltage and at the same time prevents the battery from overcharging.

Let's look at the defects that may occur during operation of the generator:

When the engine is running at medium speed, the voltage indicator shows below 12 V:

- Voltage regulator is faulty

Replace the voltage regulator

- The drive belt is loose

Tension the belt, see the article - “How to replace accessory drive belts

- Broken wires from terminals <+> or <Ш>

Repair the wires

- No or poor contact between brushes and slip rings

For repair of generator 1631.3701, see the article - "Generator 1631.3701"

For testing and repair of generator 9422.3701, see the article - "Generator 9422.3701"

Clean the brush holder from dirt, check the force of the brush springs, clean or sharpen the contact rings

- Open circuit excitation           

Eliminate the open circuit, especially carefully check the soldering points of the excitation coil leads to the slip rings and the serviceability of the coil leads

- Interturn short circuit or open circuit in the circuit of one of the phases of the stator winding of the generator

Disassemble the generator, check the stator winding for open circuits and short circuits

Replace the stator with a faulty winding

- Failure of one of the diodes of the rectifier unit

Check the diodes using instruments or a test lamp

Replace the block with faulty diodes

Rapid wear of brushes and slip rings:

- Increased slip ring runout

Sharpen and grind the slip rings

- Oil on contact rings

Wipe the slip rings and brushes with a cloth soaked in gasoline

- Increased or decreased pressure of brush springs

Check brush spring pressure

Increased generator noise:

- Insufficient amount of lubrication in bearings

Replace bearings

- The rotor touching the starter poles

Replace the generator cover

- Bearing wear

Replace bearings

- Seized bearings

Replace bearings

- Development of a seat for the bearing

Replace the generator cover

- The tension screws of the generator covers are loose

Tighten the coupling screws to a torque of 0.5 kgf.m

Failure of the bracket and mounting arms of the generator. Frequent loosening of the generator:

- Incorrect installation of the generator on the brackets

Install generator

- Increased pulley or rotor imbalance

Check the dynamic balancing of the pulley and rotor.

If the imbalance exceeds 10 gfm, balance the parts

- Increased engine imbalance

Check engine dynamic balancing