Air Blower Not Working?

In my fiat punto GO 1.2 - The air blower has stopped working when the speed is changed any speed one to four on the dial. However even when it is set to off - 0, i can feel a very slight warm breeze coming through the vent when heat is set to warmest. I have checked what i think was the correct fuse for it, but seems fine and if anybody knows if i need a new blower motor or a new resister that is under the passenger side foot well? Im sure i remeber a while ago it not working and i could smell a burning smell but after a day or two i noticed it was working again. If it is at all related to the cause of the problem I recenlty had a new ECU put in on a fault i had with the engine, if that helps?