I have a Jeep Grand Cherokee ZJ 5.2L V8. Yesterday while out on the trail I noticed by passenger door mechanism was constantly 'unlocking' the door. I figured something was loosened and didn't think much of it. On the way home my radio deck started to intermittently shut off for a few seconds and then turn back on. At the same time my headlights began flickering. I made it home and figured I'd take a look today. However; I guess I wasn't done being surprised that night. I had it in park and went to reverse and everything shut off. I put it in park and the lights came back to life but wouldn't turn over. I attempted to put it in Neutral to start it and whenever I shifted out of park everything would shut down. Anyone with any advice?