Like these guys are saying check the bulkhead. I've read through this twice and it doesn't sound like you've done that. Visually inspect them. I replaced ignition switches, ballast resistor, had the dash in and out multiple times. then I checked the bulkhead and the was the source of the problems. It sounds EXACTLY like what you are explaining. these bulkheads are a major problem area with all mopars. Like I said, my car would run fun and everything, then it would randomly do that. Even when I'm driving around it will randomly do that. check it