All lights must work
To do this, turn on the ignition and turn on the position, dipped and main beams, as well as fog lights in turn. Behind the car, the reversing lights, license plate lights and rear fog lights should work properly. The car should always have a set of replacement bulbs.
Pic. 9.16. A spare set of lamps should always be in the car. It contains not only the most important spare bulbs, but also the fuses
The car must have the following set of spare bulbs (pic. 9.16):
- halogen lamp H7, 55 W (near and far light);
- halogen lamp H1, 55 W (fog light);
- halogen lamp H, 6 W (clearance/parking light);
- round lamp P or PY, 21 W (front and rear turn signal with white or yellow bulb);
- round lamp P, 21 W (reversing light, rear fog lights);
- round lamp R, 21/4 W (brake light, side/parking light);
- round lamp R, 5 W (rear light, parking light);
- soffit lamp C, 5 W (license plate lighting);
- soffit lamp C, 10 W (interior lighting, trunk);
- LEDs (outside rear-view mirrors, additional brake signal).
Additional equipment - dipped beam headlights with gas discharge (xenon) lamps
Pic. 9.17. Xenon lamps serve all term of operation of the car. If necessary, replacement should be carried out at a workshop, since due to the presence of contacts under high voltage and the risk of explosion, self-replacement is difficult
The latest and currently the best development in lighting technology - headlights with gas discharge (xenon) lamps in a quartz glass housing (pic. 9.17). The light source is xenon gas and particles of various metal salts. The electronic switching unit ignites this mixture with a short pulse of up to 28,000 V, an arc discharge is formed between the lamp electrodes. It replaces the filament coil that has been used so far.
The advantage of such lamps is that with a power consumption of only 35 W, a xenon lamp shines twice as brightly as a 55 W incandescent halogen lamp. It also has a longer service life. Replacement of discharge lamps is possible, but usually not necessary. Xenon lamps serve all term of operation of the car. If necessary, replace such a lamp with a service station.
Another advantage is the pleasant glow of the lamp, as close as possible to daylight. This provides better and brighter illumination of the road ahead and to the side, especially when cornering and illuminating adjoining roads.
Light range adjustment
By law, the headlights of a loaded vehicle must be adjusted so that they do not dazzle oncoming vehicles.
Light of halogen lamps. On E-class models with halogen headlights, the beam range is controlled by a three-position control on the instrument panel. To do this, each headlight is equipped with a pneumatic corrector mechanism, which, when the position of the regulator changes, acts due to the vacuum generated during the intake cycle of the engine. The regulator provides a vacuum to the corrector between 0.4 bar (position «0») and 0.05 bar (position «3»), thus determining its course.
Light xenon lamps. Since the risk of dazzling oncoming traffic due to xenon headlights is particularly high, the headlights are adjusted automatically depending on the vehicle load.
Pic. 9.18. The principle of operation of the headlight range control system: 1 – a vacuum hose from an inlet pipe or the vacuum distributor; 2 - distributor; 3 - vacuum regulator next to the light switch; 4 - right headlight corrector mechanism; 5 – left headlight corrector mechanism; 6 - plug connection
Sensors on the front and rear axles detect each change in the vehicle's position relative to the horizontal axis and transmit information to the headlight range control unit (pic. 9.18). The unit is located under the rear seat. The current position of the headlights is determined in the control unit thanks to a potentiometer installed in the headlight corrector mechanisms. The control unit gives a command to change the position of the headlights with a delay, when a certain time has passed since the change in the position of the car.
Lamp health monitor
Incandescent ambient lighting for dipped beam, side beam, rear lights and brake lights are controlled by this device. When a lamp burns out, a control lamp lights up, which burns as long as this consumer is turned on. If the brake light bulbs burn out, the control lamp stays on until the ignition is turned off.
The control device recognizes a fault in a circuit if too little current flows in it. At higher current, for example when turning on a trailer, this does not lead to false alarms.