The main malfunctions of automotive electrical systems:
Battery
*Weak or dead battery
* Faulty terminals or connecting cables
* Faulty alternator not charging battery
* High leakage currents that drain the battery
Starter
* Faulty starter solenoid
* Seized or worn starter motor
* Poor connection between starter and battery
Generator
* Faulty rotor or stator
* Faulty rectifier diodes
* Worn drive belts or pulleys
Ignition system
* Faulty spark plugs or high voltage wires
* Faulty ignition coil or ignition module
*Faulty crankshaft position sensor or camshaft position sensor
Lighting system
* Burnt out lamps
* Faulty fuses or relays
* Poor connections or damaged wiring
* Faulty light switches
Electrical comfort systems
* Faulty windows, mirrors and locks
* Faulty speakers or audio amplifiers
* Faulty air conditioning or heating systems
Other possible faults
* Faulty electronic control units (ECU)
* Damaged or aging wiring
* Poor grounding
* Rodents or corrosion damaging wires
Common signs of automotive electrical faults:
* Difficulty starting the engine
* Flickering or dim headlights
* Electrical comfort systems not working
*Warning indicators on the dashboard
* Smell of burning rubber or plastic from the engine compartment