The brake light switch is a normally-open switch located near the top of the brake pedal, controlling the operation of the vehicle's brake lights by closing the circuit when the brake pedal is applied. In models with cruise control, this switch also deactivates the cruise control system when the brake pedal is depressed. If the brake lights do not illuminate when the pedal is pressed, first check the brake light fuse; if it is blown, inspect for a short in the circuit. If the fuse is intact, verify voltage to the switch using a test light or voltmeter, and if there is no voltage, check for an open or short in the power wire. Should the brake lights still fail to activate, unplug the electrical connector from the switch and use an ohmmeter to check for continuity between the switch terminals when the pedal is pressed; if continuity is absent, the switch needs replacement. If continuity is present but the lights do not work, inspect the wiring between the switch and the brake lights for an open circuit. To remove the switch, depress and hold the brake pedal, rotate the switch counterclockwise about 30 degrees, and pull it from the mounting bracket. Unplug the electrical connector, then pull the plunger outward until it is fully extended. For installation, depress the brake pedal fully, align the switch with the bracket, and avoid excessive force to prevent damage. Once installed, rotate the switch clockwise to lock it in place, gently pull back on the brake pedal until it stops, allowing the plunger to ratchet to the correct position, and finally plug the electrical connector back into the switch.