Sounds very much like when the wiring underneath my ignition switch became detached. Sometimes the wire would be touching, then everything was fine, but sometimes it wasn't, then I had the problems you are experiencing.
We had a forensic on how to sort this out, but that nice Mr. Photobucket blocked all the pictures with a ransom demand for hundreds of dollars for 3rd party hosting.
If this is your problem, you have to remove the ignition switch and take a close look at the wires. Re-solder the offending wire if you have enough wiggle room.
Personally, I relocated the switch to my left hand side panel.