Good evening all, I'm hoping someone can help me.

I have an 03 focus and before Christmas my blowers would only work on number 4. 1,2 & 3 didn't work at all. There was also a strange noise coming from where the fan motor is located, like a loud whirring sound that occurred when the fan was on and then slowed as the fan slowed when being switched off. I eventually changed the hearing resistor and this got the blowers working on all of the settings, but the noise was still there. Then I drove it to work for the next week and one morning there was a slight pop and my heaters went off and now there is nothing from any of the settings the blowers don't work at all which is really annoying this time of year. What is the cause? Can anybody help?