My main brake lights quit working..third brake light works properly

I would replace the pedal switch..cheaper way to go

better get a second look at the brake light switch, there might be two, third brake light is on a different circuit, switch light circuit goes to signal switch then brake lights

try to check the wiring ,It may be possible you have shot circuit on ur electric connections .

Replace the brake light switch located by the brake pedal. That will resolve your problem

Check the bulbs everything runs as you said the 3rd brake light works correctly so should they all. Otherwise it may be the socket could be corroded check to ensure this is not your issue.

sure the brake light switch itself is bad, there are provisions for the main and 3rd lights on most switches

If you have an aftermarket trailer towing plug on it, that's where i would look first. Something is shorting out in there, or you have a broken wire or ground somewhere. Proabably near the back where gravel stones can hit.

Most likley the brake light switch. It has 2 different sides. One for the third brake light and one for the lower brake lights. It is inexpensive and can be changed easily. Good Luck

Turn signal switch.

the third brake light requires a wire ribbon replacement,
typically on bentley gt. It is quite the job since the light is installed at the factory before the rear window is put in, There is a procedure for replacement leaving the glass in but requires replacement of the light itself and the ribbon cables,