2003 Dodge Caravan AC won't work in front

I have a 2003 Dodge Grand Caravan and when turning on the AC for the front of the van all I get is a humming sound that sounds like its coming from behind the the dash and nothing comes out of any of the vents (front panel vents, top of dash vents, and floor vents). The heat doesn't work and neither does the defrost in the front. Yet, when I turn on the AC for the rear of the van everything seems to work fine and gets cool. All four vents are working in the back. Heat works in back as well. Checked fuses and relays and all is okay. Last summer we had problems with water getting on the front passenger side floor everytime we ran the AC but after draining coolant and adding new coolant that issue went away and everything was working fine until now.