I suspect that the problem is an "open circuit" condition meaning that:
There are probably some other causes that I can't think of now. Good luck!
either your fuse is blown or the wiring is bad
Blown fuse, blown relay, blown light bulbs, short in the wiring system, bad microswitch in the brake pedal... could be any of those.
Possibly a bad brake light switch, or bad connection.
Blown fuse or bad headlight switch
Brake light switch runs through your headlight/turn signal seitch in steering column. This switch could be malfunctioning.
bulbs blown on high side or wiring shorted
Check to see if you have a blown fuse. This is often the case. Also you may try pulling the rear lights out and inspecting them for any damage or loose wiring.
check the bulb if not blown wiggle the hazzad switch brakes run through the hazzad switch just try it not positive
If all the bulbs are good then it may be a blown fuse or a defective or mis-adjusted brake light switch.
The 2000 Hyundai Excel indicator light and brake light might stop working all of a sudden because of a burned out bulb. Check all bulbs on the brake lights and turn signals. This problem could also be caused by a blown fuse or a blown flasher fuse.
It uses DOT 3
If the brake lights do not work on Chevy Venture van 2000, try to disconnect the brake switch. Then short the two contacts of the connector to check if the brake lights are now working.