Front blower dont work but back blower works - 2004 Dodge Grand Caravan

First Check the Front Blower Relay located in the IPM Fuses and Relay box in the Engine Compartment. There should be individual Front and Rear Blower Relays. The Identification and Location should be on the rear of the IPM Cover. If not check your Owner's Manual.
Switch these two Relays and recheck operation of the Front and Rear Blowers again. If the Front now works and the Rear does not, then the Relay was bad and needs to be replaced.
However the most common problems I have found is that the Front Blower only works on High. Is that the Case? Check it to be sure. If it only works on High then it is 100% the Resistor that is bad and needs to be replaced. The Front Blower Motor Resistor fail in these more often that the Blower Motor itself.
Remove the Dash Glove Box out of the Dash to gain access to the Resistor.
Let me know if this helped, or if you have additional information or questions. Feel free to contact me at FixYa.Com!