No brake lights

First Start with the Stop lights fuse Check and make sure it's good if questionable just replace it. Check to make sure you have power going into the fuse Use a 12V test light or volt meter. If you have power going into the fuse make sure the other side of the fuse has power through the fuse. Next Go to the brake light switch and test for power going into the switch if you have power put your tester on the other wire on the brake light switch and press the brake pedal, If there is power the switch is good and if not the switch is either out of adjustment or bad.
If you have power in and out of the brake light switch with the brake pedal pressed then you have to find the breadk in the wire back to the lights Oh don't forget the bulbs and the grounds for the bulbs.

on my chevy s10 if i have one brake light go out the other wont light up they are linked together same with the reverse and running lights

my brake light were working fine but now it won't turn off and signal