Hi there. Wanted to see if anyone have seen this issue before? I'm having electric issues on my 2014 plug-in prius. The 12V battery is getting pull down to 5V and symptom is that of a total dead battery. Car will start with a jump pack. Car drives normal and is charging the battery at 14v. Battery is around 3 year old but still good. Battery measures 13v when disconnected from the car but 5v when connected. No check engine light on. Any help will be appreciate it.
Are you saying that when the 12v battery is connected to the car and the car is off, the battery voltage measures 5 volts?