Can't see dash and warning lights on after replacing 12V battery

Even new batteries are sometimes defective.
Sometimes the "mechanic" doesn't get the cables tight.
OFTEN they don't bother to charge the new batteries before they install them.......which incidentally would be a good test too.
You should call the shop that installed it.
Maybe they will come to you.

 

Hope for Cause and Effect.
That is, because you just had a new battery put in...something related to that operation is the cause of the effects you are now suffering.
I would say hope, because 12 volt battery, which should be backed by warranty both in operation and installation, should be the cheapest, easiest route to resolution.

Also hope this non-hybrid mechanic didn't cross wires or mess things up installing your battery.
We may want to avoid the cost of dealership service, or even the cost of a hybrid specialty shop, but IMO whenever we have mechanics not particularly versed in Hybrid's working on Hybrids? There's risk they'll screw it up.

So I guess I'm just parroting your own concerns, " I'm just hoping this won't be a crazy expensive fix or might still be related to the 12V battery. "....Yep, me too....

If you trust this mechanic enough, I think the easiest 1st step is for them to recheck their work, and check the 12 volt battery for charge.

Best of Luck.

 

It sounds like your combination meter (CM) has failed. It seems that after fitting a new battery, the higher and constant voltage is enough to push a failing capacitor over the edge.

The dealer can fix this for you for $800-$1000 plus having your car for two (or more) weeks while they wait for a new preprogrammed CM from Japan.

If you have an appetite for DIY you can do the repair for $150 (+ $75 core deposit) by exchanging your old CM for a rebuilt one from Matt @Texas Hybrid Batteries. Click on the user name link, then click on "Start a Conversation" to make contact. You order a replacement that has a lifetime warranty and is preprogrammed with your odometer mileage. Once you have swapped it in and removed your broken CM, you return it to Matt and receive a core refund.

If you are interested to read more about this particular problem, this is a good thread. Read the first page and then skip to about page 10 Post #188.

I hope that helps.

 

While this may indeed be the case, he NEEDS to eliminate the obvious first.
That should take only a few minutes.

 

Welcome to PriusChat!!

How many hours per day/week are you driving the vehicle, both before and during the currently situation?

 

I had the dash display go off completely and had to hold the power button to turn off the car for the first time a few months ago. Scared the hell out of me as I was on a long road trip. I read about disconnecting the battery and letting it sit before reconnecting it. Grateful that this solved it for me and it has not happened since.

 

Disconnecting the battery didl not solve it. It just temporarily resets it. Next step is it dies and you will have to pull the 12 volt leads every time to shut the car off.

 

More likely is that the next step is that it fails completely and disconnecting the battery won't do anything useful.

But I guess it is possible that problem really was caused by a bad connection AT THE POST HE DISCONNECTED and his actions actually fixed it.

I do not think it is wise to just drive on like nothing ever happened.
The battery and it's connections need to be checked.....at the very least.