I have a 2007 Toyota Prius 95% of the time the dash lights won’t come on to display speedometer and fuel gauge. The only thing I’ve found that resolves the issue til next time I turn it off is to disconnect and reconnect multiple times the wire harness to the small batery in the back and keep doing it until the door open dinging starts to ding then I can start it and everything lights up. Sometimes it works on first disconnect and reconnect other times I have to keep doing it repeatedly for sometimes 45 mins or longer disconnecting and reconnecting. What is the problem??
Poor battery connection.
How old is that 12v battery?