The sources of electricity on the car are a generator and a battery (battery) connected in parallel. When the engine is turned off, consumers are powered only from the battery. During engine operation, power is supplied from the generator and the battery is being charged. When a large number of consumers are switched on at the same time and the engine speed is low (idling) the energy of one generator will not be enough, in this case the battery will be discharged. This must be taken into account in order to avoid a complete discharge of the battery.
The nominal operating voltage of power sources and consumers is 12 V. Depending on the operating conditions, the voltage in the network can fluctuate within 11-14.5 V. In vehicles with a fuel injection system, the supply voltage of some consumers is 5 V. Most electrical circuits are protected by fuses installed in the mounting block. The engine ignition system circuit, the starter power circuits and the battery charging circuit are not protected by fuses.
Consumers of electricity are the starter and the ignition system of the car (ignition coil or ignition module, spark plugs), lighting and light signaling devices (headlights, taillights, side turn signals), control devices with sensors, electric motors (windshield wipers, washer pumps, heater and radiator fans), sound signal, rear window heating element, fuel supply and control system for the injection engine.
The consumers are switched on by switches on the instrument panel and steering column (steering column switch) and in the car's interior. Voltage is supplied to most consumers via the ignition switch (lock), located on the left side of the steering shaft bracket. The power supply circuits of the horn, cigarette lighter, brake light lamps, interior lighting lamps, and the side light switch are always connected to the battery. The ignition switch is used to switch the starter circuits, ignition system, power supply system, and engine management system (for injection engine). The ignition switch consists of a housing, a mechanical anti-theft device with a lock and a contact part secured in the housing by a clamping ring. After removing the key in the "parking" position, the locking rod of the anti-theft device extends from the lock and enters the groove of the steering shaft, blocking its rotation. Voltage from the battery and generator is supplied to the ignition switch input contacts "30" and "30/1".
High-power consumers are connected via electromagnetic relays. The relay for turning on the rear window heating, headlight wipers and washers, and high beam headlights are located in the mounting block. The ignition relay, the hazard warning light and turn signal relay are installed in the passenger compartment on the engine compartment bulkhead behind the instrument panel.
The sound signal consists of two signals of different tones (in a variant design from one) and is located in the engine compartment. It is attached to a bracket on the left radiator frame pillar.
(The text is copied from the online resource: «vazbook.ru»)
Low-voltage wires of the PVA type with elastic insulation made of polyvinyl chloride, resistant to oil and gasoline, are used to connect electrical equipment devices. The wires are collected in bundles. To facilitate searching in bundles, the insulation of the wires is made in different colors. Depending on the current strength in the circuit, wires of different cross-sections are used. The negative terminal of the battery and the engine are connected with a wire with a cross-section of 16 mm².
The transmission of high voltage pulses from the coil to the distributor and from the distributor to the spark plugs occurs via high voltage wires. In cars with fuel injection, the ignition coil is connected by high voltage wires directly to the spark plugs. For each engine model, spark plugs are selected individually, in accordance with the design features of the engine (see "Spark plugs").
Attention! When repairing electrical equipment, to avoid short circuits, it is necessary to disconnect the wire from the negative terminal of the battery.