In theory, you can fix your own brake switch. But since you have (obviously) never done this before, I suggest you leave it for someone with more experience.
You can fix the brake booster switch in your 1991 Jaguar by replacing the brake booster switch. In most cases when the brake booster switch does not function properly the only way to fix it is to replace it.
brake light switch at the top off your brake pedal the little rubber bumber is worn out or the switch is out.... very easy fix
Check the fuse, the bulbs, and the brake light switch.
Probably the switch on the brake pedal,
You will need to change the brake light switch. The brake light switch can be found below the dashboard on the drivers side.
check your fuses and the brake light switch above the pedal
The brake light switch must be broken or out of adjustment.
under ure brake pedal u have a brake switch simple fix.
Brake light switches are usually attached somewhere on the lever of the brake pedal. When you depress the brake pedal this action in somw way activates the switch either by opening or closing a circuit. Because the lack of brake lights can cause some serious accidents, if your switch is "sticking" you should replace it immediately for your own safety and the safety of the other drivers in your community.
Adjust or replace the brake light switch.
To fix a Nissan brake switch, first, locate the switch, typically found near the brake pedal. Inspect the wiring and connectors for any damage or loose connections. If the switch is faulty, it may need to be replaced; you can remove it by unscrewing it from its mount and installing the new switch in reverse order. After installation, test the brake lights to ensure proper function.
if it isn't a fuse or lamp problem, check the brake lamp switch on the brake pedal, if you unplug the switch, and jumper the connection, and you have brake lamps, replace the switch...