Display going wacky, AC goes on and off by itself

Your complaints suggestyto me, you might issues with either the AC circuitry in the MFD, or there's a partial contact problem with one of the AC connectors.

Have the fuses looked at.

Do you have a scantool? If you do, you might have an AC system related codes logged in the AC ECU of the car.

 

I agree that you should get the codes and find out what complaints your car has. Not hard at home with inexpensive tools. Dealer will charge to read the codes, but that's the quickest way to find out. The auto parts stores do not generally have scanners that read Prius specific codes, but I've seen reports that some do.

Also, from what I've experienced and read about here, a low 12V battery can generate a wide range of mysterious symptoms in the Prius. So I think the first thing I'd do is check its condition. It only takes a minute and costs nothing to eliminate it as a problem. Then get after those dtc codes.

 

Exactly

Perfectly right.

 

Be sure that your mechanic can read all the Prius codes. It has a bunch that are not programmed into generic scanners.

 

Hope you get solid answers there. And inexpensive ones, too!

 

if it was the speedo display, (multi function display = MFD) you may have a bad solder joint. if the dealer confirms, it is very expensive, but there are rebuilt options much cheaper.

how old is the 12v? not every mechanic really knows how to test them properly.