My 2 corner brake lights don't work but the 9ne in the window does. I've looked for a fuse but can't find one. My running lights and blinkers and all the other lights work fine. I replaced the bulbs but not that either. I don't know what else to do

 

From the black wire to the brake light bulb socket, verify you have good continuity to ground. Next verify that when the brakes are applied you are getting battery voltage on the green wire.