Check wiring for 12v also the brake switch on the brake pedal.
you do not adjust the brake lights check the bulbs or check switch top of brake pedal.
Bad bulbs or brake light switch.
check that you have double filament bulbs in tail lights
Working brake lights are important for safety reasons while driving. It is important to check all of the wiring, if the brake lights are not working and the fuses and bulbs have been checked.
If the brake lights & horn are on the same fused circuit the most likely cause of the problem is an open circuit before the fuse.
Assuming you have checked the bulbs, check the brake light switch.
Check the bulbs, check the fuse, check the brake light switch, in that order.
It needs checked out but both the hazard and brake lights go through the turn signal switch.
Did you check the switch on the brake pedal assembly?
Have you tried brake light switch located on brake pedal or in that area?
Likely to be the brake light switch on the pedal at fault if the bulbs and fuses are good and other lights work ok.
on some cars the tail lights and brake lights are totally different bulbs gain access to the bulbs and have someone push the brakes so that you can determine which bulbs are the brake lights and replace the tail lights