Brake light on and why
Have you check all of the light bulbs? If yes, then check the ground next and then check the fuses. Lastly, if all of those check out, it is most likely the brake switch behind the brake pedal.
Check the brake light switch. It is defective or out of adjustment.
The brake light switch may be bad or out of adjustment. The switch is located just above the brake pedal.
Replace brake light switch.
I have never seen one. If you want them off you have to press on the emergency brake a little.
Look under the dash on the 1996 suburban, and locate the brake light switch on the brake pedal arm. Remove the switch nut, and slide the switch out. Unplug the wires from the switch and install the new switch.
Have you checked the brake fluid level in your brake master cylinder in your engine compartment ? a low level will turn on your brake light in the dash
when this light is on it means that there is something wrong with your anti-lock-brake system and you should go get it checked.
The brake light switch is located on a bracket behind the brake pedal support.
The ground for the brake lamp. When the tail lights are off, the tail light circuit can act as a ground for the brake light. When the tail lights are on, it can't.
Low brake fluid in master cylinder? Parking brake not fully released?