It starts. None of the dash instruments light. The radio works. The fan blows, but the power on the AC unit doesn't work. I checked the fuses in the engine compartment and they are all fine. There are some relays in there, but I don't know how to check them. The power windows work but the power door locks don't work. It's a 2003 Chrysler Town & Country van. It started having problems at the end of last week. I cleaned the battery terminals which were caked with corrosion. That fixed it for a few days, but it's now worse than before. This is the first time the dash has gone dead.