The Renault / Dacia Sandero is equipped with a three-phase alternator with electromagnetic excitation, a diode rectifier unit and a built-in voltage regulator

The generator is driven by a poly-V-belt of the accessory drive from the crankshaft pulley.

The generator consists of a rotor, a stator, a rectifier unit, a brush assembly with a voltage regulator and two covers.

A pulley is installed on the rotor shaft. To cool the generator parts, ventilation holes are made in its covers, and an impeller is made on the rotor from the side of the front cover.

The stator has a three-phase star-connected winding.

The winding leads are soldered to the rectifier unit.

The rectifier unit is installed under the generator casing together with the brush assembly and voltage regulator.

An excitation winding is made in the rotor, the leads of which are soldered to two slip rings.

The rotor shaft of the generator rotates on two ball bearings.

The front bearing is pressed into the front cover of the generator, and the rear one is pressed onto the rotor shaft and is held on the rear cover of the generator.

The voltage regulator is non-contact, electronic, combined with a brush assembly in a common non-separable body.

Brushes - carbon, spring-loaded.

Possible generator malfunctions, causes and remedies

- Reason

Remedy

When the ignition is switched on, the battery discharge warning lamp does not light up:

- Broken wire between generator, ignition switch and warning lamp

Eliminate the open

- Signal lamp burned out

Replace lamp

- Defective generator

Replace or repair the generator

Battery discharge warning light does not go out after engine start:

- Weak tension of the alternator drive belt

Adjust the belt tension

- Defective diode bridge of the generator

Repair the generator

- Short circuit of the wire between the generator and the signal lamp to ground

Insulate the wire

The battery discharge warning lamp is on when the ignition is off:

- Defective generator

Replace or repair the generator

The generator does not charge the battery:

- Oxidation of the battery terminals

Strip, fasten and lubricate the wire end caps

- Battery defective

Replace the battery

- Weak tension of the alternator drive belt

Adjust the belt tension

- Defective generator (diode bridge)

Repair the generator

The battery is being recharged:

- Defective generator (voltage regulator, diode bridge)

Repair the generator

- Increased voltage drop in the generator-battery circuit

Check, clean, tighten or replace the contact connections in the ignition switch, fuses, connectors; check the connection of the generator body to ground.

Removal and installation of the generator

Let's consider the removal process on the example of a fully equipped car with a K7J and K7M engine, with a K4M engine, the only difference is in the generator mounting.

We remove the accessory drive belt (article - Checking and replacing the Renault Sandero accessory drive belt)

Снятие и ремонт генератора Рено СандероСнятие и ремонт генератора Рено Сандеро

Disconnect the block of wires from the generator by pressing the block retainer with a screwdriver

Unscrew the nut securing the wire end

Снятие и ремонт генератора Рено Сандеро

Disconnect the wire from the generator output

We remove the front bumper (article - Removing the wheel arch liners and bumpers of the Renault Sandero car)

Снятие и ремонт генератора Рено СандероСнятие и ремонт генератора Рено Сандеро

We unscrew the mounting bolts of the air conditioner compressor and, without disconnecting the pipelines, we take the compressor to the side

We unscrew the power steering pump bolts, do not disconnect the pipeline and hose from the pump

Снятие и ремонт генератора Рено Сандеро

Disconnect the wiring harness holder from the attachment bracket with a screwdriver

Снятие и ремонт генератора Рено СандероСнятие и ремонт генератора Рено Сандеро

Unscrew the three mounting bolts of the generator

We move the power steering pump aside so that the hose does not interfere with the extraction of the generator, and remove the generator.

Installing the parts in reverse order. Tighten the generator mounting bolts with a torque of 21 Nm (2.1 kgf.m)

Generator repair

Let's consider how to replace the voltage regulator and rectifier unit.

If the rotor or stator winding is out of order, the generator must be replaced as an assembly.

We remove the generator as described above.

Снятие и ремонт генератора Рено СандероСнятие и ремонт генератора Рено Сандеро

Unscrew the screw securing the back cover

Unscrew the two nuts

Снятие и ремонт генератора Рено Сандеро

Remove the back cover of the generator

Снятие и ремонт генератора Рено СандероСнятие и ремонт генератора Рено Сандеро

Unscrew the three screws securing the voltage regulator

Removing the voltage regulator

Снятие и ремонт генератора Рено Сандеро

We check the ease of movement of the brushes in the brush holder and their protrusion.

If the protrusion "A" of the brushes from the holder is less than 5 mm, change the voltage regulator assembly with the brush holder

Снятие и ремонт генератора Рено Сандеро

We check with a tester in the ohmmeter mode of the rotor winding resistance by connecting it to the slip rings.

If the ohmmeter shows infinity, then there is an open circuit in the windings and the rotor must be replaced (it is better to replace the generator)

Снятие и ремонт генератора Рено Сандеро

We check the diodes of the rectifier unit.

We connect one wire to the mass of the rectifier unit, and the second to the output of the diode

Снятие и ремонт генератора Рено Сандеро

Then we swap the wires in places. The diode should only conduct current in one direction.

If the diode passes current in both directions or does not pass at all, then it is faulty.

We check all the valves in this way.

Снятие и ремонт генератора Рено СандероСнятие и ремонт генератора Рено Сандеро

To replace the rectifier unit, unclench twelve contacts with a screwdriver

We unscrew the two fastening screws and remove the rectifier unit

We assemble the generator in reverse order.