A parasitic battery drain occurs when an electrical component continues drawing power after the vehicle is switched off.
Common Causes
- Interior lights left on
- Faulty alternator diodes
- Aftermarket alarms
- Defective relays
- Malfunctioning control modules
- Faulty audio systems
Symptoms
- Dead battery after parking
- Frequent jump starts
- Slow engine cranking
A technician can identify the drain using a multimeter and circuit testing.