Ok, heres the deal, Im leaking coolant from my radiator. I dont know why I suppose there is a crack in it...I havent taken out the radiator to inspect it but I know its leaking from there cuz I can see it drip from the radiator. Second, I think my thermostat is done for because the fan doesn't turn on, I overheat, the heater doesn't work, and the lower radiator hose is cold. So my question is could the faulty thermostat cause all the problems or is it the lack of coolant in the radiator causing the overheat?

 

Lack of coolant will definitely cause this problem but just to make sure fill up your rad make sure there is no air left in it then see if you get heat but replace your rad asap.