2002 Dodge Ram Dash lights off on, headlights off on no key

Replaced ignition sw, small harness. New battery, I took headlight switch out of loop still has problem.
When I pull fuse to dash/radio I can simulate problem at times.
head lights turn on in driveway then turn off. NO key parked.

When head lights turn on, dash light in vehicle go off.
While driving dashlights go off going down hill at times.
If I put in reverse at times dash lights come on.

If everything works, when stopping during day, when I open the door chime rings that key is in ignition, but is not, then when key is put in no dash lights.
Repair shop says don't have a clue.
I need map of where things are under hood.
I think this is a swinging short somewhere.
Thanks