My son had the same problem on his 1995 Monte Carlo. The brake light in rear window worked , as did the tail lights and emergency flasher but no brake lights came on when pushing the brake pedal. Anyway , the problem was in the turn signal switch. This involved taking the steering wheel and column apart , taking the airbag out ( careully ) and it was more than I wanted to handle. The mechanic charged 227.00 including part and labor. .
Check the switch on the brake pedal
brake light switch would be most common cause
Possible ground issue at the taillights.
BAD BRAKE LIGHT SWITCH AT TOP OF BRAKE PEDAL
The BOO (Brake On/Off) Switch may need to be replaced. If it is bad, it would cause the brake lights to NOT illuminate when the brake pedal is applied.
More than likely it is the brake light switch that is attached to the brake pedal.
brake switch located on the top of the brake pedal
Check your brake light switch at hte brake pedal.
The most likely cause is a bad brake light switch (if none of the brake lights illuminate) but if its only one of the brake lights, try changing the bulb. Even if they still work as running or turn lights because they have a double filament and may still work partially, but not as brake lights.
Check the switch adjustment on the brake pedal arm.
Check the bulbs - they are doubloe filamented with the smaller being for brake/turn signals Check the fuses
Blown fuse, bulb, or bad brake light switch.
Check the bulbs, fuse & brake light switch on the pedal.
Check the fuses and if they are good then check the brake light switch.
the brake light switch is out of adjustment. Readjust the switch.
A broken or out of adjustment brake light switch.
You probably need to replace your brake light switch. It's near the top of the brake assembly, beyond a trim panel. The fact that all three brake lights don't work rules out problems in the multifunction switch (the cause of similar problems affecting only the two rear lights.)
There's a switch that the brake pedal engages when pressed that makes the brake lights go on. this switch may be stuck.Or the peddle staying on switch
a blown bulb or loose wire.
Check the brake switch located on your brake pedal shaft. May have to be replaced.
have you checked your fuses?
It is possible that a wheel speed sensor is bad. This will cause the anti lock braking to not read the wheel correctly which would be a brake problem that would cause a light.
brake switch ???