General information
Starting and charging systems are the main components of the engine electrical equipment. Since the operation of these systems is related to the operation of the engine, they are considered separately from other on-board electrical equipment, such as lighting, controls, etc., which are discussed separately in the Chapter Onboard electrical equipment.
The rated voltage of the vehicle's onboard power supply is 12 V. Grounding is organized along the negative pole.
All models come standard with a sealed, maintenance-free or low-maintenance battery. The battery is recharged by an alternator with a belt drive from the crankshaft pulley.
The starter is made according to the scheme with pre-engagement and is equipped with a built-in traction relay. When the engine is started, the relay plunger moves into position and engages the starter pinion gear with the flywheel ring gear before power is applied to the electric motor. The starter drive gear is equipped with an overrunning clutch that protects the electric motor from turning when the engine speed exceeds the permissible value.
Detailed information on the principle of operation and maintenance of various components of the systems is given below in the relevant Sections of the Chapter. If any components fail, they are usually replaced.
Precautionary measures
When servicing components of electrical equipment systems, special precautions must be taken to avoid the risk of failure of semiconductor elements, as well as to prevent electrical injury.
Be sure to remove watches, rings, and other metal jewelry when servicing electrical equipment. Even with the battery disconnected, discharging capacitors by accidentally grounding their terminals can result in electric shock or severe burns.
Do not reverse polarity when connecting the battery. Components such as the alternator or electronic control units contain semiconductor elements that can be damaged if the wires are connected incorrectly.
When starting the engine from an external power source, or connecting the charger, also observe the polarity of the wires (see the relevant Section at the end of the Manual).
Never disconnect electrical wiring from the battery, alternator, or diagnostic equipment while the engine is running.
Do not allow the engine to turn over a disconnected generator.
Never test for generator output voltage by grounding its terminals.
Do not use ohmmeters equipped with a manual dynamo to check for continuity in the circuit.
When performing any electrical maintenance work, ensure that the negative cable is disconnected from the battery.
Be sure to disconnect the battery, alternator, and components such as the power/ignition ECUs before using arc welding to avoid the risk of damaging them.
The audio system included as standard on a Skoda car is equipped with a built-in coded blocker that prevents the possibility of unauthorized activation of a stolen radio. Protection works even with a short-term disconnection of on-board power. Before disconnecting the wires from the battery, make sure that you have the code to disable the radio blocker (see chapter Onboard electrical equipment).
Note. On removable radios, protection may be activated 24 hours after the unit is removed from the receiving slot.
On models equipped with an anti-theft alarm, before disconnecting the battery, do not forget to turn off the alarm with the key - the lock is located at the rear of the main control unit for the anti-theft system.