Buick/Olds: Rear Window Brake Light, turn signal switch, brake light switch

Question
Harold, I realize your a Chevy expert, but thought you may have an answer. My 1989 RWD Fleetwood window brake light quit working (not the bulb).Is this wired to the brake switch or where does it get its power? I recently had the brake switch replaced as it was sticking on. Any help would be appreciated. Thanks Keith  

Answer
Yes the 3rd brake light runs directly off of the brake light switch. The other brake lights run form the brake light switch and then through the turn signal switch because the same bulbs are used for turn signals.
The wire for the 3rd brake light is spliced into the orange wire coming out of the brake light switch. I'm not exactly sure where the splice is on your car but it is between the brake light switch and the steering column harness. You should also check the ground wire off of the 3rd brake light socket.