Visual inspection
* Check batteries for corrosion, leaks and cracks.
* Inspect the battery terminals to make sure they are clean and secure.
* Check the drive belts for the alternator and water pump for cracks or looseness.
* Check wires and cables for wear, damage and corrosion.
* Be aware of any unusual odors, such as burning rubber or plastic.
Battery check
*Check the battery voltage (should be around 12V).
* Perform a load test on the battery to determine battery performance.
Generator check
* Check the alternator voltage (should be around 14V with the engine running).
* Check the voltage regulator to make sure it controls the generated voltage correctly.
* Check the generator brushes for wear.
Checking the starter
* Listen to the sounds when the engine starts. If the starter clicks but does not turn, there may be a problem with the battery or other electrical components.
* Check the starter solenoid relay to ensure it is operating properly.
Checking electronic systems
* Check the functionality of all exterior lights (headlights, side lights, turn signals).
* Check the operation of interior lighting devices (instrument panel, interior lighting).
* Check the operation of the windows, mirrors and air conditioning.
* Perform diagnostics via OBD-II port.
Additional Tips
* Use a multimeter to measure voltage and resistance.
* Clean electrical contacts and connectors from corrosion.
*If any problems are found, contact a qualified mechanic.
* Regular maintenance of the electrical system will prevent serious problems.