Brake lights are not working?

Okay, one of the first items to check would be the brake light switch. That is assuming that the turn signals and hazards do work and cause those lights to flash. The brake switch is up under the dash and has 2 terminals, if you don't have cruise. 4 terminals if you do have cruise. The easy way to test the switch is to just unplug the connector and jump the two terminals in the connector that go to the orange and white wires, do the brake lights come on? Yes = bad switch, no = more testing. With the 4-pin unit you jump the two "rear" terminals.
Failed switches were common. Now if the hazard lights don't work as well then, it's possible the fuse failed. It's fuse 17 in the image. A possible test as well is to turn the hazards on and off a few times and see if the lights come back. The hazard switches were problematic at times and if toggling the switch makes the light work, replace the switch.
Wiring diagrams are somewhat sparse for those years as they were mostly done out of the wiring books.