still trouble w/ tail lights

[67Fleet]

well, I'm still puzzled why my tail lights are not functioning properly. The blinkers both work, but the tail lights and brake lights don't. I've checked the entire fuse panel with a test light and all are good. Replaced both relays. Checked both bulbs out back. I just don't get it. Any other ideas? It shouldn't be a ground if the blinkers are working right? Please help!! Otherwise I'm gonna take it in saturday morning to an auto electrical place and the guy told me it'll probably cost me $125.00!!!! I've gotta get it fixed before the Rod Run in daytona thanksgiving weekend. I'm running outta options.