2000 Camaro SS Starting problem

I have a 2000 Camaro SS with 21000 miles on it. 1000 miles ago, I had a no start, not a click, nothing. The battery was fully charged. The vehicle was towed to the Chev dealer, where they replaced the ignition relay, and the key ignition in the steering column. Last week the same problem occurred. I removed both the starter and ignition relays from the little black box under the hood, and cleaned the contacts. The car has been starting fine until this morning. I removed the starter relay, cleaned it, but still no start, not a click, nothing. All the lights are bright, the radio plays, the windows go up and down like they should. I wiggled the relays a little bit, and then the car started. I got the car home and checked the charging system. I am getting 14.2 volts at the battery. Should I replace the starter relay, or is something more going on that I am not aware of?
Any help would be greatly appreciated.
Gus