Ok, so for the longest time my f90bt has worked fine, When I turn the car on the headunit is very bright usually and when i turn my headlights on it dims a little for night. Now it is always dim, I didn't change anything that I know of. The only thing I can think of is that the wire used to tell the headunit to be bright or dim came off.... I have no idea how that would of happened but I will check it in a few days when I get time to pull it out, anyone else have any ideas?

I found the issue, turns out somehow my brightness got reset to 0 :/ no idea how since I'm the only one that drives the car and I know i didn't do it

brightness will not change the light illumination, it changes screen brightness