I have a 2007 F150,The temp control doesn't work properly, either it's too hot or too cool.I replaced the thermostat but it hasn't changed.I also have a problem with the heater air flow ,speed 1 works like it should,speed 2 is OK but speed 3 is the same as 2 and speed 4 works as it should .I replaced the resistor #YH-1715 but no change .Has anyone had either of these problems and if so could you help me out?

Thanks VM
Terry