Mercedes S-class W202

1993-2000 of release

Repair and car operation

Mercedes W202
+ 1.2. The general data
+ 2. Maintenance service
+ 3. Engines
+ 4. Greasing system
+ 5. Cooling system
+ 6. Heating, ventilation
+ 7. Ignition system
+ 8. Fuel system
+ 9. Transmission
+ 10. A running gear
+ 11. A steering
+ 12. Brake system
+ 13. A body
- 14. An electric equipment
   14.1.2. Measuring devices
   14.1.3. Technics of measurements
   14.1.4. Electric equipment checks
   14.1.5. A sound signal
   14.1.6. Replacements of safety locks
   + 14.1.7. The storage battery
   + 14.1.8. The generator
   + 14.1.9. A starter
   14.1.10. The traction relay
   + 14.1.11. Illumination system
   14.1.12. Devices
   14.1.13. The instrument panel
   14.1.14. Lamps накаливания on the panel of devices
   14.1.15. Light switch
   14.1.16. A radio receiver
   + 14.1.17. The aerial
   14.1.18. Dynamics
   + 14.1.19. Rubber brushes of screen wipers
   14.1.20. Jets стеклоомывателя
   14.1.21. Washing atomizers of headlights
   14.1.22. A 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. "Галогенки"
+ 14.2. Electroschemes

14.1.26. "Галогенки"

Principal cause of fast failure галогенных lamps in cars – the big current proceeding through a lamp at the moment of inclusion as resistance of its thread in a cold condition is many times less, than in нагретом.

In this connection it is recommended to limit a starting current by means of the additional resistor included consistently with threads накаливания галогенных of lamps. After lamp inclusion it is resistance it is short-circuited by means of the relay of the pressure established in parallel to a lamp.

Lack of such devices is necessity of use of one or two electromagnetic relays, details insufficiently reliable, especially in the conditions of the car testing vibration. Besides, at the moment of inclusion spasmodic increase of a current, though and to smaller size all the same takes place, than at usual schemes of inclusion of lamps.

Experts develop the contactless device not demanding application of the relay and providing smooth increase of a current in a lamp. The device consists of the additional resistor R1, two diodes VD1 both VD2 and электролитического the condenser With.

At inclusion of a thread of a passing light on a clip 1 the positive potential moves. Thus diode VD1 connects in parallel a thread of a lamp the condenser With, and is consecutive with it – resistor R1.

At inclusion of a thread of a headlight the positive potential moves on a clip 2, and the condenser With headlight threads through diode VD2 are connected in parallel.

At such scheme of connection pressure on lamps EL1 and EL2 accrues smoothly.

Resistance of cold threads of usual automobile lamps of near and far light approximately 10 times less their resistance in нагретом a condition. The constant of time of heating of a thread of a lamp makes 0,0014–0,003 with.

For an exception it is inadmissible the big current in the course of lamp inclusion it is necessary, that speed of increase in resistance of a thread of a lamp was more speeds of increase of pressure. It is reached by installation электролитических condensers in capacity 4000-6000 мкФ, rated voltage 25 Century

If to take advantage of these councils along with increase in service life of lamps the life of the accumulator because of decrease in a starting current and increase in smoothness of its increase will last also.

About correct adjustment of headlights...

Correct adjustment of headlights in большей to a measure concerns culture of driving, rather than to any technical problems. Похтому we will talk about why in due course headlights start to give dim light, probably, and sufficient on deserted highway, but absolutely inefficient on recovered, especially, if the counter stream is great.

Sometimes sin on the generator and a pressure regulator. Here there is a true share: malfunctions of these devices are appreciable by "the movement" of a light stream as though submitting to quantity of turns of the engine. It is clear that unimportant work of the generator and a pressure regulator influences not only on efficiency of headlights – the accumulator, or not receiving a high-grade charge, or, on the contrary, first of all suffers – receiving it is a lot of it, from what the electrolit "boils". Headlights in this case play only an indicator role though superfluous pressure strongly reduces a resource of lamps. Constant dim radiation arises for other reasons: or strongly the reflector becomes soiled or becomes covered by corrosion, or there is a dark touch on an internal surface of a flask of a lamp.

If the durability of a reflector depends on many factors even quite serviceable lamp "types" a dark touch for any 30-50 thousand kilometres. Its efficiency in that case percent on 20 below the new.

The reflector "lives" longer. In modern cars the reflector and headlight glass are, so to say, an integrated whole that first of all provides the optimal light bunch, and in the second – tightness. The tightness lack promoted penetration in a headlight of a dust which then burnt on a reflector and reduced it светоотдачу. The Same occurred and to a moisture actively condensed on a reflector that caused corrosion.

About five years ago with corrosion tried to struggle in any improbable way, filling in in a headlight a red brake liquid. The fashion on this, is faster harmful, rather than a useful invention has passed, but there was other extreme measure – plexiglass "points" on glasses. Besides, that such protection reduces светоотдачу, "smearing" a direction of beams, it вызвает strong heating and обгорание a reflector. What in that case use from the glass protected from stones if the reflector suffers, – it is not clear, as how it has already been told, glass and a reflector nowadays represent an integrated whole? By the way, therefore it be no point to buy "lens" separately: good light from such headlight never to achieve.

At last, as to adjustments. Even the perfect headlights supplied галогенными with lamps, can appear on the journey useless if they are adjusted somehow. Not everyone, and not always has a possibility to make adjustment at the stand. Therefore rather quite good results give the old, well tested ways of "house" adjustment. The car establish on an equal platform, measure 30 metres and put on a mark, let us assume, a brick. One of the headlights, included on a passing light, something veil, and in the second – rotate adjusting screws so that light exposure border vertically to bring to the put brick. The same do and with other headlight. A headlight regulate in a horizontal direction, but already without a brick: here it is important to achieve, that bunches from both headlights did not fork and did not converge in the middle.

The electric motor

The most widespread malfunction in electromotors – isolation breakdown in windings. We will admit, you have put the car on parking, and to switch off "yard keepers" have forgotten. It is enough three-four hours, that the winding has burnt through. Or have left a rag in подкапотной to a niche where draughts of screen wipers move. The motor gets jammed with the same result for its windings.

Sometimes isolation manages to be restored, having sustained an anchor in bank with engine oil. The much bigger effect is given by slightly warmed-up drying oil if to sustain in it an anchor in some stages, doing daily breaks for drying.

The same trouble – winding breakdown – overtakes also the electromotor of a washer of a windscreen. There is it frequently from a carelessness of the automobile owner when or the tank with water is empty, or the liquid has frozen, or jets-raspryskivateli or the pump filter are "tightly hammered, and in the block of safety locks in an electromotor chain costs"жучок".

In general with safety locks it is better not to joke. It will allow to avoid not only the short circuit terminating sometimes in a fire, but also it is easier to find out malfunctions.

For the beginning motorist should be gold corrected: it is necessary to begin searches of the reasons of malfunctions of an electric equipment with the block of safety locks.

I remember, when I bought the car first in the life in shop has paid attention that the control lamp of a charge of the accumulator burns. Then the assumption was born that, should be, or generator brushes have not got used yet, or "makes a fool" of a pressure regulator (at that time cars were completed with mechanical relays-regulators of the Bulgarian manufacture. Happened, they worked on "recharge", and the bulb) lighted up. Replacement of the relay-regulator of results has not given: the generator simply did not develop energy. Replacement щеточного knot too has appeared useless.

It was necessary to remove the generator, preliminary plums from system cooling liquid and having dismantled the thermostat. Check of windings of the generator and "bridge" of diodes has shown that everything is all right. Only then, having done all this unnecessary work on absolutely new car, I have guessed to glance in the block of safety locks. Certainly. A corresponding safety lock in a chain of excitation of a winding of the generator it was not simple.

So if at you the generator has refused, begin check with a safety lock. Let even it is whole, be not too lazy to smooth out a zone of its contact. Only after that undertake directly the generator.

However do not hasten with its dismantling and dismantle. At first check up щеточный knot. Presence large having chopped off on brushes, their considerable deterioration or замасливание can already serve as a generator cause of a failure.

Pay attention to a condition of contact rings of an anchor which are visible in a window into which it is inserted щеточный knot. Scratches and grooves are deduced by a grinding skin, then polished. If these operations do not give result, it will be necessary to undertake for выпрямительный the block, preliminary having disconnected wires from the storage battery and the generator. Block check make by means of a control lamp. The negative pole of the battery is deduced on the generator case, positive – through a bulb – on a conclusion "30".

If the bulb lights up, means, выпрямительный the block is punched also it it is necessary to change. Happens, the truth that прбивает either positive, or negative gates of the block. But, perhaps, it is better not to press in these subtleties, as separate replacement of gates does not practise.

At last, about a starter. It, perhaps, one of the most durable knots of the car though it "works" in the severe conditions. Even when the engine, in a starter capitally is under repair, happens, change only brushes and smooth out contact rings.

The weakest place of a starter – обгонная муфта, or "бендикс": in it, happens, scatter or persistent rollers lie down. And then at engine start-up hum is heard only: the starter rotates, but does not turn a motor flywheel. "бендикса" washing sometimes helps with kerosene or acetone. But умельцы, as a rule, развальцовывают the holder with rollers and or is changed by all details of a holder, or carefully they are washed out.

Other widespread malfunction is connected not with a starter, and with oxidation or breakage of tips of the special wattled tyre connecting the engine with a body, that is "weight" (the tyre is located under the engine) more. In this case the starter publishes characteristic clicks or in general "is silent", if, of course, "silence" is not caused by other reason – a detachment плюсового conducting of the relay of a starter. Check is anyhow necessary. If relay conductings on a place – undertake the tyre. But if conductings nevertheless has jumped out, do not try to insert it, without removing a starter – will waste in vain time. The starter should be dismantled.