2007 Ford Falcon parking-running lights malfunction

My above Ford has a problem with the parking lights-running lights as they do not work with regular low beams. If I flip the high beams on then all lights come on. Note that my dash lights are also out unless high beams are on. I can activate running lights/parks without my low beam head lamps activated however, as soon as I turn the low head lights on (low beam)the all dash/running lights/tail lights etc go out.

I have check fuses, replace head lamp relay without any success. Any suggestions?

much appreciated.