91 liberty wagon dash lights

[scotty.bmx]

hey, i installed a new head unit into my car.
the dash lights weren't working so i had another look at my wiring and the best result i can get is dash lights work untill my head lights are turned on...
and that isnt any help.
can anyone help me with the wiring?
i have a repair manual with the wire diagrams but this is no help.
any results would be good so i can legally drive at night again.
cheers,

[ROB-80E]

SO when you have your parking lights on, the dash lights work? If this is the case....when you flick to your main headlights, and the dash lights go out, let me know if your parking lights are also not working (front, rear and number plate lights).