I have a 2003 Excursion Diesel and just experienced the same problem! The EATC was working fine until I turned the truck off yesterday afternoon. When restarting it I turned the EATC panel off and after starting the truck I attempted to turn the A/C panel on which was totally unresponsive! After checking other Ford EATC Diagnostics on the web, I decided to check the forum and found your post. I just went outside flicked the lights on and off a few times and lo and behold the EATC Display became alive again! Thanks! But do you have any idea what causes that? I am certain that the Ford Dealer will tell me I am nuts, but the truth is, it worked!My 05 does that, I have found that turning the lights on and off bring the ac controls back on. I took it in 3 times for this problem and always by the time the tech got to it, it worked fine and passed diagnostics.