Hey, I recently changed out my hybrid battery with a new one and the car runs better than it ever has with me! It's really been wonderful. I bought the car with 330k and now it's got over 380k.

The problem is the 12v light is coming on. The 12v is from 2017 and it came on a lot before I installed a new hybrid battery. Whenever it would come on, I would just do the ignition kill trick while the car was going over 20mph and then it would go off for a day or 20 miles or whatever. Now, the light turns on sometimes when the car is in neutral at stop lights (car is a manual). It's aggravating because the motor doesn't always kick back on when I put it into gear.

 

Bad 12V
Bad ground straps.
Bad DC-DC Converter
Bad IMA battery

When it comes one, can you make it go out by revving and holding the engine at 2000 rpm for 30 seconds?

 

It goes out just as soon as I rev the engine at all, or when I begin to accelerate.

the wiring harness on the 12v is new or came off of a used car of the same year.

I don't see how it could be the ima battery because the one I just installed has 4 years left out of a 5 year warranty and is doing it's thing on the ima gauge beautifully.

could it be the converter then?

 

Again:

Bad 12V
Bad ground straps (there are 3 of them, and you have no idea as to their condition - "new or came off of a used car of the same year" - which is it? "new" vs 14+ years old makes a difference)
Bad DC-DC converter
Bad IMA battery

Note that the last two are almost certain to have DTC associated with them.

 

Went to have the battery tested. It was in very good shape. Then I noticed the posts were loose enough to almost pull off, so I bought a shim for the posts and got them tight. The problem was gone for a few outings now it's dying while in gear, and I have to shift into another gear and then back again. Then the oil pressure light came on for a second.

I did just replace the cam plug seals because I was losing 2 quarts every three weeks. Now that appears to be over. I also just bought a pcv valve and will install that here soon. Oil level is alright. I did have to dump some havoline in the motor and it wasn't the called for weight. Maybe that's creating an oil pressure issue?