Brake lights are out  but the third brake light still comes on? where do I start ?
 
replace your brakelights lol
 
 
Okay first off did you check the bulbs, did you check the contacts? If not theres your place to start.
- 2004 Cavalier - 124k, owned since new
 
also check the sockets thats the reason for a recall that is on going. 
Semper Fi SAINT.  May you rest in peace.