Noticed when starting my truck that I had to set clock, and when I got home 1 day I turned truck off and all went dead, couldn't even start it. Then after a few seconds power came back on and started. I got to thinking back and remembered starting truck and a/c was on but heating on drivers side, turn off and restart and it does fine. It's an 07 and far as I know battery never been changed--( battery maybe problem?)