My Caravan had a bad PCM. Just had the dealer put a new one in on Saturday 12/22/2012. Ran great that afternoon, they also charged the battery. The next day Sunday went to go to the store and the van was dead. So got a ride and went and bought a new battery worked fine that day also ran on Monday. Tuesday morning (Christmas Day) went to go somewhere and it is dead again. I put a new starter in this last summer. Also has a new belt. The lights are very dim inside and headlights not working at all. Figure it must be the alternator but don't want to start replacing more parts if it could be something else. Any ideas, also calling the dealership in the morning to see what they say. I did notice after they installed the new PCM the airbag light stays on while driving it.
Use a digital multimeter across battery posts, everything off, what is the reading? The generic spec for a full charge is around 12.6 volts. You can't test anything if the battery is down. Will the vehicle start using jumper cables? If you can get it started, we can check charging system.
Can you check for applicable trouble codes. You may be able to check mil codes, yourself? Again the battery needs to have a full charge.