S-class W202 Mercedes

1993-2000 of release

Repair and car operation

W202 Mercedes
+ 1.2. General information
+ 2. Maintenance
+ 3. Engines
+ 4. Greasing system
+ 5. Cooling system
+ 6. Heating, ventilation
+ 7. Ignition system
+ 8. Fuel system
+ 9. Transmission
+ 10. Running gear
+ 11. Steering
+ 12. Brake system
+ 13. Body
- 14. Electric equipment
   14.1.2. Measuring devices
   14.1.3. Equipment of measurements
   14.1.4. Electric equipment checks
   14.1.5. Sound signal
   14.1.6. Replacements of safety locks
   + 14.1.7. Storage battery
   - 14.1.8. Generator Diagnostics of malfunctions of the generator
   + 14.1.9. Starter
   14.1.10. Traction relay
   + 14.1.11. Lighting system
   14.1.12. Devices
   14.1.13. Dashboard
   14.1.14. Filament lamps on the dashboard
   14.1.15. Light switch
   14.1.16. Radio receiver
   + 14.1.17. Aerial
   14.1.18. Loudspeakers
   + 14.1.19. Rubber brushes of screen wipers
   14.1.20. Jets of a stekloomyvatel
   14.1.21. Washing nozzles of headlights
   14.1.22. Screen wiper and its engine
   14.1.23. Protect the car
   14.1.24. Anticreeping "immunodeficiency"
   14.1.25. Why headlights grow dull
   14.1.26. "Galogenki"
+ 14.2. Electroschemes

b47c026d b47c026d

14.1.8. Generator


Engines of Mercedes cars of the S-class work with the three-phase generator of an alternating current. Depending on model and equipment generators of various capacity are established.

The generator is put in action by means of a cranked shaft and a maple belt. Thus the rotor rotates approximately with the doubled frequency of rotation of a shaft of the engine by means of the winding of the excitement located in rigidly established winding of a stator.

By means of coal brushes and contact rings the current of excitement proceeds through an excitement winding. The electromagnetic field is thus formed. The provision of an electromagnetic field constantly changes in relation to a stator winding according to rotor rotation. Thanks to it in a winding of a stator the three-phase current is developed. But as the storage battery can be charged by only a direct current, the three-phase current will be transformed in constant by means of the rectifier established on a diode payment. The regulator of tension changes a charging current by means of inclusion and switching off of a current of excitement according to degree of a razryazhennost of the storage battery. At the same time the regulator supports to constants working tension about 12 Volts irrespective of frequency of rotation.

Safety measures at work on the generator of an alternating current

At work on the generator of an alternating current pay attention to points of data below instructions. Complete dismantling and repair of the generator of an alternating current carry out in a specialized repair truck.

If the additional storage battery is connected (for example, for simplification of start-up of the engine), surely pay attention to that identical poles of storage batteries among themselves incorporated.

At connection of the charger of a wire of the last connect to the corresponding plugs of the storage battery. During a charging disconnect from plugs of the storage battery a wire from a flexible partition between a body and the engine and a positive wire.

Do not allow to work to the engine without the storage battery.

Never close накоротко plugs on the generator of an alternating current and on a regulator.

Never make a perepolyusovka of the generator of an alternating current.


1. A plug 30 wire (In +)
2. Plug 61 wire (Д +)
3. Bolts
4. Contact protection
5. Generator

1. Disconnect from the plug of the storage battery a weight wire (–).

Disconnect only at the switched-off ignition, the actuation device of system of injection of fuel differently can be damaged. Before disconnection of wires from plugs of the storage battery it is necessary to read also the recommendations which are available in appropriate sections.

2. Weaken a tension of a maple ridge belt and only then remove it from a belt pulley of the generator.
3. Raise in front the car. If is available, remove the bottom cover of a motor compartment.
4. Remove from a generator flange contact protection (4).
5. Unscrew on the generator electric wires (1) and (2).
6. Get on the holder bolts (3) and take the generator.


1. Insert the generator, tighten fixing bolts with the moment of 40 N of m.
2. Screw a wire on the plug 30 with the moment of 15 N of m, and to the plug 61 with the moment of 5 N of m. Get contact protection.
3. Lay and pull maple a belt.
4. Establish the bottom cover of a motor compartment.
5. Attach to the plug of the storage battery a weight wire (–). Establish time on hours, and also enter an anticreeping code for radio.

Check of a charge voltage of the generator

1. Connect the voltmeter between a positive and negative pole of the storage battery.
2. Start the engine. In the course of start tension can decrease till 9,5 Century.
3. At frequency of rotation of a shaft of the engine in 3000 rpm tension should make 13,0–14,5 V.Eto proves that the generator and a regulator work.

Replacement and check of coal brushes of a generator / regulator of tension

The regulator of tension is built in in the holder for coal brushes. It is possible to replace coal brushes separately, some skill for this purpose is, however, necessary; on the average they wear out after passing by the car about 120 000 km. We recommend to replace coal brushes slightly earlier.


1, 4. Bolts
2. Cover
3. A holding ledge
5. Regulator
6. A ledge for connection with the car case
G2. Generator

1. Remove the generator.
2. Unscrew bolts (1), disconnect spring clips and remove a protective casing (2). Unscrew bolts (4) and take aside a regulator (5).
3. Replace coal brushes, for this purpose unsolder a multicore connecting flexible wire.
4. Check wear of contact rings, if necessary grind them absolutely and polish.


1. Insert new coal brushes (And) and springs (In) in the holder of coal brushes (C) and solder connections.
2. That when soldering new brushes tin solder could not rise highly in a flexible wire, support a multicore connecting flexible wire of brushes flat-nose pliers.

Because of highly risen tin solder multicore connecting flexible wires become rigid, and coal brushes become disabled.

3. Establish a regulator of tension and rigidly screw it. At installation pay attention to that the ledge for connection with the case of the car adjoined to a regulator.
4. After installation of new coal brushes check them on ease of a course in their holders.
5. Get a protective casing on the generator and screw it.
6. Establish the generator.