Help!! Fan not turning on!
 

So I have a 2004 Mazda 3s....for sometime my fan switch would not turn on my fan, I got the wiring diagram for my vehicle from a tech buddy at my dealership. I brought it to my local mechanic and we don't know what it could be. We think it's electrical but I want to fix it on my own because he is too busy with work but don't know where to start looking on the diagram. I also just noticed that when I switch my lights on that it usually lights up around my switches but now it doesn't, I would even tap on the side for it to come on and it would sometimes here and there but now it doesn't come on at all. We checked the fuses and even switched the 40s out under the hood, they all seem to be good. I checked the fuses in the vehicle as well fuses are good. I have my glove compartment out and all. Where do I look next? Also I do hear something turning on when I turn the switch on but no air blows, my temperature switch works, ac button works as well. The fan use to sometimes come on later on too but of course doesn't any longer, especially when I needed it in below 0 degree weather! Any suggestions?! Please and thank you!