My battery went dead again on my 06 Mustang GT. This is the third time. I opened the right door and it was from one second to the next the interior lights went off and that was it. It happened right there in front of me, so it's not the battery. Standing there in the garage looking at the car and talking to myself, I noticed the right interior light kept going on and off, so I took both battery cables off and there was still life in the battery. It is like I said in one my earlier posts, there is something that does this whenever it feels like it, there is no pattern. I think I just about had it.