Defective Trunk Light: Similarly to the interior lighting, inspect the trunk light and its switch to ensure they are working correctly. A stuck trunk light or a faulty switch can keep the light turned on, leading to battery drainage over time.
Faulty Radio or Amplifier: In some cases, a problem with the car's radio or amplifier can cause a key-off battery drain. If the radio or amplifier stays powered on even after you turn off the engine and switch off the key, it can slowly discharge the battery. Have these components checked by a professional to rule out any electrical issues.
Parasitic Draw: Parasitic draw refers to the continuous consumption of power by the vehicle's electrical systems even when the ignition is off and there are no lights or accessories turned on. This draw can be caused by various components, including:
- Faulty wiring or connectors that allow current to flow unnecessarily
- Damaged or malfunctioning electronic modules or accessories
Battery Malfunction: It is also possible that the key-off battery drain is due to a problem with the battery itself. If the battery is old, damaged, or has a faulty internal connection, it may not be able to hold its charge properly, resulting in a gradual loss of power even when the car is turned off.
