sup people I have 2000 CLK 320 and the brake lights aren't working or the cruise control. I checked the fuses and they seem to work. the brake lights dont need to be changed, i'm assuming it has to do with the electrical? i went to checkers and he said it may be the relay? i have no idea. please help

 

its most likely the brake switch. or also called the stop lamp switch. its behind the brake pedal under the dash