People, the weirdest of the failures just happened with my 2008 Civic:
The radio and clock only turn on if I also turn on the headlights. If I turn the headlights off, the radio shuts down (and demands the code afterwards)
The remote is not working anymore, it does nothing. The alarm is also down. No sound, no nothing. I had to lock the doors manually.
Everything else looks normal: The engine starts ok, the battery level is 13-14V, the electric windows, I checked some fuses, everything on place.
The radio is original, no changes in wiring have been made, I just parked the car for a while and it was like this when I came back.

Any ideas? Thanks!

 

Solved it. Fuse number 23, under the hood, the one specified as Back Up in the owner manual, 10A, was blown. I checked all the fuses, this was the only one blown. But the radio backlight is still weak when the headlight is off, even adjusting it to max.

I think the problem occurred when I left the keys in the ignition for an hour to charge the phone.

 

New update: problem not fixed. Once I replaced the fuse, the backlights and front turning lights turned on and don't turn off anymore, even after removing the keys and shutting everything down. Still don't know what it is.