Diagnostics of the car electrical system
Diagnostics of the vehicle electrical system includes checking the following components:
Battery
* Check the battery voltage with the engine off and running.
* Check the battery terminals for corrosion or looseness.
* Check the electrolyte density (for lead-acid batteries).
Starter
* Check the starter for clicking or grinding noises when trying to start the engine.
* Check the starter solenoid relay for proper operation.
* Check launch cables and connections.
Generator
* Check the generator voltage at the terminals with the engine running.
* Check the alternator belt for tension and wear.
* Check the generator diode bridge for breakdown.
Fuses and relays
* Check fuses and relays for blown or faulty components.
* Use a circuit tester to check the continuity of the fuses.
* Check the relay contacts for corrosion or looseness.
Electrical wiring
* Check electrical wiring for wear, damage or kinks.
* Check terminals and connectors for corrosion, looseness or damage.
* Check the grounding of electrical components.
Control modules
*Connect the OBD2 scanner to the car and diagnose the fault codes.
* Verify the functionality of the control modules by checking their power, grounding, and signals.
Additional components
* Light (headlights, flashlights, turn signals)
* Window lifters
*Alarm
* Radio and sound system
* Sensors and actuators
Tools needed for diagnosis
* Multimeter
* Ammeter
* Circuit tester
* OBD2 scanner
* Set of keys and screwdrivers
Diagnostic tips
* Break the task into smaller parts.
* Check power supplies and grounding first.
* Use the car wiring diagram as a guide.
*If you are unsure of your diagnosis, seek help from a professional mechanic.