I have a 2008 Prius, 155k on the odometer. I'm an engineer, but not a not a mechanic, but will try to describe everything I can about what's been going on. Due to an unfortunate circumstance, the hatch was left open for an extended period of time and the 12v battery drained. There were no issues before that happened It sat like that for a few weeks. I was able to jump start it and drive it (the dash did not light up), but the next day it was dead again. It was the same battery that was in the car when I bought it in 2011, so I got a good amount of life out of it. I bought a new battery and installed it (thanks for all the advice here on that job). No joy. I checked the fuses and found that the 15a "AM2" fuse (under hood) was blown, as was the 10a "Gauge" (under dash). Both were changed out. When I got to check the voltage of the battery (multimeter), it was at 12.65. it is now at 11.85, so I know that needs to be put on charge. When I tried to start the car, the ready light did not come on, but I get the check engine light. Right now I don't have the means to read the codes. The door open indicator does come on, but nothing other than the check engine light comes on the dash. I can feel the resistance increase on the brake pedal, so I presume it means that system is getting power. The display screen doesn't come on. My plan is to charge the battery and then see what happens. Possibly the battery charge dropped during all the time I have been fussing with things. Quick questions: Can the 12v battery be charged while in the car or do I have to take it out first? Without being able to read the codes, is there any advice you can give me on what to do next, other than take it to a dealer? Many thanks for your time and assistance! P.S. I also have a 2008 and a 2013 Prius (Trius family) so I will probably be spending a bit more time on here in the future.
You can charge the battery at the battery while it is in the car or go to the main fuse box under the hood and there is a place there meant to jump start and charge the car. This information should be in the owners manual. Welcome to Prius Chat.
I think they have battery minders or so that can charge the battery in the car. I just hope the "new" battery isn't bad too?! From your explanations, it appears the AM2 fuse has blown again. Recheck the fuse(s), and see. With that fuse blowing, that tells you you need to replaced the inverter pump. It's shorting internally already. If that isn't the problem, then there must be a short somewhere on the HV contactor's circuitry.
You can disconnect the inverter pump and start the car if the AM2 fuse is blown again. Just disconnect the pump wires, replace AM2 and see if the car goes to ready. If it does you know the pump is the problem. Just don’t drive it with the pump disconnected. That would be bad.
If there don't have headlights,may the fusible link under the plastic cover is blown. Usually caused by reverse polarity jump.