Have you replaced any tail light or turn signal bulbs lately? It is a common mistake to replace a combinaton turn signal/tail light bulb with the wrong one. I ran into this problem on an older Buick. I replaced a bad turn/tail bulb with the wrong bulb. The new bulb fit but when I stepped on the brakes the dash lights would come on. What I did wrong was I put an 1156 (single contactor bulb) in the turn tail socket which was supose to take an 1157 ( double contactor bulb). Check your turn tail bulbs and make sure they are correct.
a fuse
The fuse probably blew that controls the dashboard lights.
did you check the fuse?
You need a new fuse
Check the switch at the brake pedal .
Check stop light switch - usually located at the upper end of the brake pedal under dash
Which light are you asking about? Dashboard location would help -- Brake lights mean the brake is being applied, but I'm sure that's not what you're asking.
Check your fuse.
Some cars have a knob for the headlights. If this knob is turned left or right when pulled out, it changes the brightness of the dashboard lights from off to full brightness.
You may have a bulb that that brunt a element which than crossed the other element cause all lights to come on a one time. I have seen this before. If this does not light all bulbs when the brakes are applied, then I would be looking in the front lights, if it does I would look in the back lights.
Because it is British.
A blown fuse can make your dashboard lights to not work in your 1993 Chevy Blazer Tahoe. A burned out bulb can also cause this.