Okay so I have a 1999 Chevy Cavalier I just bought and have been steadily replacing parts myself. Now that I have it running we discover that the brake lights do not work, in troubleshooting the issue I discovered that the tail lights do not work either. However, the side lights work when the headlights are on and the blinkers both work. In addition the backup lights ALL work. Could this all be part of the brake switch? My Brother in law seems to think it is the ground wire (which I cannot find to save my soul. HELP??!!

 

Try the brake switch that is loaced by the brake pledle

 

Check all the fuses, the bulbs and the sockets for good connections. The taillights and the brake lights are a different circuit. Not sure about the Cavalier, but they may both be on the same fuse. Probably not.