i turn the key, but nothing....tried a new battery, new ignition switch, nothing

Don't forget about the starter motor!!

Have you tried waiting 3 minutes and trying again. That's what I do with my 1999 Aurora and it starts right up. I'm sure it's in the key or ignition but not sure if I need to go to the expense of replacing them. It started happening too often. It was very difficult, even for the dealer to determine what the problem was. They finally changed the lock cylinder and that fixed the problem.

Also check to see if you have any related trouble codes stored in the PCM.