My son was changing his battery in his 05 Scion XA and accedently placed the cables on backwards (he's only 16, I should have been watching him). After this boo boo, the car starts but it seems the interior fuse panel lost all power. None of the fuses are blown in the panel but things like brake lights, wipers, tail lights, power windows, AC, radio, etc. are all out. Im thinking its a main fuse that sends power to it but Im not sure where it's at or if this is even the problem.
Any advise would be appreciated.
Thanks,

 

Hey I read your question but I'm having the same issue, I'm just curious if you found out the problem. All my fuse is a good, I haven't checked the relays but car runs and drives. __-Thanks Anthony

 

Most likely blew out a fuse or fusible link in main fuse-box under bonnet.
This is only way to know for sure if fuse is good or bad.
I'd be trillionaire if I had penny for every time I heard, "Fuse looks OK", but actually didn't conduct any electricity.