Chevy s10 brake light

Neither the hi mount stop lamp or the lower brake lites, work? Did you check stop lamp fuse? Did you check voltage and grounds? the orange wire at the stop lamp switch is hot all the time and fuse protected. the stop lamp switch is activated by brake pedal arm, follow the arm up to find the switch. You can use a test lite to check for voltage on the orange wire. when switch is activated, the white wire goes hot and carries brake lamp voltage. the switch should be activated when you step on the brake pedal. your lower brake lamps are wired through the multifunction switch. the hi mount brake lamp isn't wired that way. voltage and ground both are important.