You by-passed the pressure switch, connecting the two wires from the pressure switch together, and no brake lights. As Jarrid mentioned, that rules out the pressure switch.
If the running lights and turn signals are working, the tail light housings would appear to have a good ground.
With the two wires you removed from the pressure switch, there should be a green wire and a green + purple wire. The green wire should have 12V when the ignition switch is in the 'run' position. Check that first.
If you find 12V on the green wire at the pressure switch, then go into the trunk and disconnect the green + purple wires from each of the sockets in the tail light housing. Connect the green and green + purple wire from the pressure switch together again and go check the voltage on the connectors you disconnected in the trunk. You should see 12V at each connector. If you see 12V at each connector, then check the light bulbs and check the continuity between the light socket housing and chassis ground.
Note: When you are testing, do not leave the ignition in the 'run' position with the car not running. You can cook the ignition coil. While you are doing your tests with the ignition in the 'run' position, temporarily disconnect the wires from the ignition coil's "+" terminal and you will be ok. (Make sure the wires you disconnect from the ignition coil terminal are not touching anything.)
Mike