my battery light comes on right after I start the van. What could be the reason?

Check battery connection

My 2012 Chrysler Town & country minivan, is having issues with the battery light, van not starting, lights strobing, door locks repeatedly locking and unlocking took it to a dealership and they replaced the battery within 30 miles the battery light came back on returned it to the dealership after reading this article I asked for them to do diagnostics on the voltage regulator in the computer the dealership refused saying it was the alternator after I picked up my van I had it tested independently and the alternator was testing at 14 volts we are continuing our chase of the issue we removed and checked the fuses and the light went off again we will keep you guys informed. The dealership asked what website that I had got my info from because Chrysler does not want everyone fixing there own car because they are not certified to work on the vehicle. I would not tell the website but as I walked into the dealership to pick up my van, and the sticker in the door was for CarGurus recommend dealership.