factory wiring diagram for rear tail lights, turn signals etc???

brake lights and turn signal may share a bulb , in that case the brake light runs through the turn signal switch , everything needs a ground too .

Tail lamps and park lamps can be considered the same. Note the diagram. See the park lamp relay, check that 15 amp fuse at the top, in diagram, also check for voltage at the fuse, hot all the time, use a test light. at the bottom of diagram, see the arrow with the A, that is voltage for rear lamps. Violet wire with white tracer. If you think that park relay has a problem, relay in diagram is not serviceable, you might be able to wire up external relay for park lamps. Does tag license lamp work? The diagram is from my database, not the best, but, what I could afford. good luck