I press on my brake and my radio lights go dimmer, 2010 Kia Soul

car starts, runs and drives perfectly?
AC or heater blower works on high?
head lamps work fully and brightly.?
tail lamp (park) all glow? ?
brake lamps work and are bright.
check fuses?
look for connections to the radio loose or damaged

AM Radio dead means the antenna is missing wires to it bad. or missing.
FM may work say on 1 stations if the stations is like 5 miles away, all stations that are under say 25miles must work or the antenna is bad. FM, and vastly farther for AM.
we do not know where you live( a town) so can never guess
what stations are in range to you. see?

Check the wire connection to the brake light, follow the wire as far as you can, A pinched or split wire can minimize electric current flow enough to cause a light to flicker or dim, also check Fuse Box,

It is generally caused when your onboard diagnostic (obd) system detects a fault in your emission system. It could be anything from a loose gas cap to a faulty sensor. You need to have your car scanned to see what error code is causing the light to come on. Places like Auto Zone usually provide this service for free.

no there is no adjustment for that you might just need a new dash cluster where the led lights might be failing in the dash

look at the bulb itself and see if the filament is broke and laying on the other part of the bulb.. otherwise it may be in the signal switch itself..

I had a similar issue on my 2006 sonata and found it caused by the anti theft sensor malfunction. Replaced and solved issue.

Go a auto part store,Autozone,Oreilly's or Advance,have them check your battery and alternator,it's free and only takes a few minutes,other things to look at,are your battery cables clean and tight,is the serpentine belt good,not turning loosely.

may want to check the brake pedal switch located on top of the brake pedal arm. If all fuses looks good, replace the brake pedal switch, which can also cause to not shift out of park.

Could be a loose connection somewhere...but usually it's caused by a bad or misadjusted brake light switch. also sometimes thie switch has a plastic or rubber cap on the switch end that touches the brake pedal arm, and that wears out with age or use.

It's usually easy to replace.