if you shorted the terminals of the brake light switch and the lights worked, but they don't when you push the pedal ..... bad brake light switch? check it with an ohmmeter
lite sw to park position and brake lites go out .... wires on switch wrong? what you think are brake lights are actually tail lights? [double filament bulbs, bright filament is brake]
"rear park lights" are called tail lights, they should be on with either the park light position or headlight position .... bad switch or wiring wrong?
you haven't said if the system ever worked, if it's all stock or an added on turn setup and hash wiring .... I'd guess you have some messed up wiring on a project, possibly a bad switch or 2, but it's time to get out the meter and wiring schematic and sort it out, the multiple plugs underneath might be wired wrong or damaged - could have a bad connection in the plugs or on a switch - could have a bad ground at the back - could easily be multiple problems
Bill
