lilyellowrex

Hi, I've been having issues with the brakes on my bro's rex. None of the brake lights come on except for the third brake light, so I know it's not an issue with the brake switch. Thought it was a short, so I pulled the harness and checked for any cuts/burns/breaks, also changed all of the bulbs just because they didn't look too great but they still didn't work. Then checked the other side of the connection and traced the wires back to the fuse box and checked the stereo wires for shorts and found nothing. I was wondering if there are any other suggestions of things to check or if anyone has any experience with an issue like this? Any lighting diagrams? thanks in advance.

The car is an 88 crx si with all stock interior.