1997 Dodge Caravan Battery light.

My car battery light came on this week so my husband took the altenator out, got it tested---it tested fine and the battery is a year old maintenence free battery that also tested fine. He also replaced the serpintine belt. He noticed when he took the altenator out that there was a faulty connection with the wire to the altenator so he fixed that and put it back together and the van worked fine for three days. Then this morning the battery light came on again. What could this problem be? We also have had issues with the indicator lights (rear wiper/ac/rear defrost) flashing for the first 20 or so minutes that the car is on. The dealership wasn't able to figure out why it was doing that and it ran fine for the past two years with this problem---so Im wonderiing if this could be a part of the issue. We are on a tight budget and any information that could point us in the right direction to care for this problem is greatly appreciated. Thank you.