Brake lights not working.

My right and left brake lights are not working, the brake light on the hood under the spoiler is though. I have changed the bulbs and checked all fuses. So what component would prevent the right and left bulbs from lighting brighter when I brake?(The light bulbs work like normal when I have my headlights on or turn signals on)

Any help would be appreciated, thanks.

Oh, and my car is a 99 Pontiac Sunfire

You said you checked the bulbs and fuses, which leaves wiring. So, get to tracing...

The power for the brake lights (other than the center light) go through the signal switch in the steering column. It has to do this to allow for the same light to be used for both signal and brake. Pull the steering column cover off and make sure that you have power going into the switch when you press the brakes, if you do, then make sure there is power going out (it goes to each side seperately). If there is nothing coming in, chase it back down to below the dash, if it is going in but not coming out, then you likely have to replace the switch.