About a year ago I installed a Kenwood DDX812. I haven't had any problems with it until yesterday. The truck had been sitting in the garage all week (went on vacation). I pull the truck out and turn on the radio, all I get is a blank screen and no audio. I took everything apart, it all looks good. Now, if I disconnect the wire harness the deck will turn on and work fine. If I turn it off and turn it back on again, it will not properly until the harness is disconnected again.

Any ideas of suggestions?