RE: 2004 Caravan AC Blower not working??
There is a relay for the blower motor. The relay comes before the fuse, so I would check to make sure the fuse is getting power (So its important you check the right fuse!)
If the fuse is NOT getting power, switch the relay with another relay that you know is good. If that fixes the problem, well, obviously, you just need to get a new relay.
If the fuse is getting power, its very probable that the blower motor resistor block has crapped out. (I know this is usually the cause of the blowers not working on the trucks). The blower motor resistor simply translates the blower speed setting you select on the A/C-Heater control into a resistor on the ground path for the blower motor. (At "high" speed, there is no resistance, at "low" speed, there is much resistance)
I'm not sure where exactly the resistor is located on these vans. The wiring diagram I have has no pictures, but simply says, "Right Side of HVAC". In the truck at least, its reachable from the passenger-side foot area. The resistor shouldn't cost too much, about $10-15.
Let us know what you find out.