Husband got a Prius 08 off a friend of his , car was working great until about 3 weeks after car wouldn’t start. Everything was on, but it wouldn’t say “ready” to start driving. Besides having to change the Cadillac converter (which we still need to do) , we changed the battery thinking it was the problem. Car worked fine about a week but with the key inserted. Now it will only turn on and run but every once in a while.
A new battery solved the issue for a few days and now I suspect the battery has been discharged to a point the various computers do not run. Try to recharge the AGM battery to hold 12.8-13.0 volts and try again. If this solves it, probably means the 12v battery is not charging properly. It could be grounding issues, a bad inverter or a faulty new 12v battery. Are there any OBD2 codes?
If I had a Cadillac, I'm not sure what I'd convert it to. Seriously, posting the trouble codes here is probably the best next step.
