Two weeks ago my 2001 3.3 dodge caravan shut off after I had left it running in park with the air on for about 5 minutes. I then tried starting it again and then it just "clicked" when I tried to start it. I had power because I could turn on my headlights. The odomoter showed Cruise and then P1684 and then Done. The tow truck driver came and then the car started and kept running for about three days and then it happened again. The same code showed up again. The mechanic put it on the scanner and said the alternator was showing different voltage so he replaced my alternator and told me that was the problem. I drove it for two more days and then it happened again with the same code appearing again. This time the mechanic changed the instrument panel found under the hood of the car and test drove it and said it was fine. I was driving my car on the highway and it felt like it was stalling but it engaged again. the next day, I drove it for about an hour and then it completely shut off again and this time it would start but it clicked off again and wouldn't start. I don't know what the problem is and I know what the code means but wouldn't this mean that I would have no power to turn on the lights if the battery wasn't working? I have a strange feeling that it's not something big but it's costing me a fortune to locate what the problem is. Help!?!