The brake light switch is usually a normally open type mounted on top of the brake pedal; when the pedal is pressed, it completes the brake light circuit and turns on the brake lamp. Non-cruise control models have two terminals while cruise control models include two more terminals to drive both circuits of the cruise control in parallel for simultaneous activation. If the brake light circuit is the problem then if both lights are off inspect the fuse, but if only one is out than the problem is most likely the bulb. If the fuse and bulbs are good and the lights are still not on; then check for battery voltage on the switch side. To give the switch a try, give the negative battery cable a loose connection, the electrical connector to be disconnected, and using an ohmmeter, place it to the 2 lower terminals; the gauge should read no limit when the pedal is not pressed and a lower value when it is pressed. In turn, a test light can be used, one side of which is connected to the check constant voltage and the other side is switched on when the pedal is pressed. When the pedal is applied and if the switch is operating fine then there should be volts between switch & brake lights. To replace, first, disconnect the negative battery terminal and the electrical connector of the switch next, to unbolt the switch and remove it you need to unlock the locknut. Installation is the reverse and is done with the use of a feeler gauge of the said thickness, where the locknut is then tightened, and the electrical connector reconnected to adjust the switch.