READY won't turn on, and general maintenance

This is a two part question.

2007 Prius with 220,000 miles. Bought third hand (from a friend) in 2016 with 160,000 miles.

The ready light doesn’t turn on, and in fact I haven’t seen any of the side dash lights come on besides the blinkers, car door, and seatbelt. No tire pressure check, or oil check. I always thought it was some inconsequential issue, but after reading threads I realize that the “ready” light should turn on. This has been going on for at least 20k miles without a problem running the car.

I checked the 12v battery and it showed 11.9. I haven’t replaced it in the 60,000 miles I’ve had the car over the last 6 years. This winter got down to -15 regularly at night. Sometimes when I start the car the battery meter in the center console is very low. Now I just saw something about replacing the combination meter assembly?



Maintenance.

Last year my HV water pump went down. The air conditioning stopped working, as did cruise control, and the warning light came on in the center console. I got code P0A93. I had it replaced and after doing research realized that I was supposed to have changed the coolant in the inverter. I want to avoid this mistake again by making sure that I do all of the important maintenance. I used to take my car to a good shop, but not one that specialized in Prius. They treated me well but didn’t make any suggestions.


Previous owner at 159,000 miles: changed spark plugs, serviced fuel injector

181,000 miles: transmission fluid replaced? That’s what it reads with “Toyota WS Fluid”

In the last 60,000 miles I’ve:
-New tires
-Breaks checked (likely to change one set this time)
-Oil changes at regular intervals
-Cabin and engine air filter multiple times
-Headlights replaced


What should I have done?
-Transaxle fluid replaced? Or did that happen at 181k?
-Differential?
-12v battery - if so, do I need to get specific with the mechanic?
-Break Flush?
-Engine Coolant replaced?


I live out west and take it on long hauls at least once a year (8-10 hours in one day). I also ride on dirt roads... anything specific for physical checks?


THANK YOU!!!!!