Ford Ranger Heater Not Blowing Air?

I have a 2007 Ford Ranger Sport with a V6. Last summer the A/C didn't blow much air, for about two weeks. My heater only worked once in a while and for a week now nothing blows air. I've replaced the thermostat, temp sensor, blower motor resistor and the air door actuator. I checked both fuses in the fuse box under the hood and both are fine. Any suggestions? I'm tired of driving in the cold.