I have a 1995 Dodge Ram Van B2500 3.9 liter V6. The fan would take 10 - 15 minutes to come on and now doesn't come on at all. It sounds like the AC works but not the fan. I assume the fan needs to be replaced. Is it under the glove box on the passenger side?

 

If it doesn't work on any speed, it *might* be the fan itself, but, check the resistor block as well. They burn out over time.