The charging problem isn't related to the 12 volt system as long as your 12 volt battery is good. Is your Check engine light on ? does the charger work what happens when you plug the HV charger in.
You can have a bad number 5 contact a bad OBCM does the car drive ?
I explained it wrong. I have a discharging issue. My 12v is going dead spontaneously. Just replaced it as I thought the battery was the issue. It actually does charge, it just doesn't stay charged. The 12v drains almost overnight. Any help is appreciated. I was taking it to Vancouver last week, only to learn they just lost their Fisker sponsorship. San Fran is a long way from Seattle. Thanks.
You need to use a fluke meter or a meter that is capable of showing MA draw I use a clamp style one around the 12 volt disconnect.
Once that's in place you can start pulling fuses and check the meter after you pull one fuse at a time and see if the draw reduces. If pulling the fuses doesn't show a decline then you have to start with computers. Finding a 12 volt draw is very time consuming. Make sure it's nothing simple like the vanity mirrors or glove box light staying on
Thanks Harleyguy, I've got some good multimeters. The car doesn't charge from an external charger. It times out after a few minutes. If the battery is dead and I connect a charger, will the meter readings be similar and reliable as well?
From what I've read your car doesn't charge when you try charging using the HV battery charger ??
The 12 volt battery needs to be fully charged in order for the HV battery to charged . Put the car in ready mode check the voltage at the APM that's the computer close to the firewall with the red cover on it you can use your multimeter from the top to check if the car is charging