Mercedes S-Class W-140

1991-1999 of release

Repair and car operation

Check of system of a charging

If you found malfunction in charging system - malfunction of the generator cannot be the unique reason. Execute the following checks:

   a) Examine a driving belt and be convinced that it is tense and it is not damaged. At detection of damages replace it (address to Head Routine maintenance).
   b) Be convinced that bolts of fastening of the generator are reliably tightened;
   c) Check conducting of the generator and all sockets. All contacts should be reliable and not oxidized;
   d) Check the corresponding safety locks located in an impellent compartment (address to Head Onboard electric equipment). At detection burned down eliminate the reason of a peregoraniye of a safety lock and replace it (at a peregoraniye of the corresponding safety lock you cannot start the engine or include any of devices);
   e) Start the engine and be convinced that from the generator extraneous sounds (whistle or squeal are not distributed can signal about malfunction of bearings or wear of brushes);
   f) Be convinced that the storage battery is completely charged. If one of a banok is damaged, the storage battery can consume a superfluous current;
   g) Disconnect tips of wires from the storage battery (at first negative). Examine plugs of the storage battery and tips of wires. At detection of traces of corrosion carefully clear them (address to materials of Head Routine maintenance). Attach tips of wires to plugs and reliably tighten.

Measure tension on plugs of the storage battery at the switched-off engine. It should be about 12 Century.

Attach the voltmeter to poles of the storage battery and get the engine. Increase turns until stable tension will be established. Indications of the voltmeter should lie in limits from 13.5 to 14.6 Century.

Turn on as much as possible electrodevices (headlights, the heater fan, heating of back glass etc.) and be convinced that the voltmeter shows from 13 to 14 V.Napryazheniye can fall, but should increase again (for this purpose to you, probably, it is necessary to increase slightly engine turns).

If tension on the voltmeter exceeds the specified sizes, replace a tension regulator.

If tension on the voltmeter is lower maximum admissible, as a cause of defect worn-out brushes, weak springs of brushes, refusal of a regulator of the tension, the burned-down diode, break can serve in a winding, and also malfunction of rings of a collector. The condition of brushes and rings can be checked, but if will change nothing, the generator should be removed for carrying out check, repair or replacement.