I have been having problems with my AC. I have replaced switches, resistor, and checked fuses and relays.

I had problems with the fan speed blower switch and control switch. Seem as the blower motor ages it still runs but cause wire and switches to heat up and melt. The most common way it seems to manifest its self is ruining your fan blower resistor and fan speed switch but other things can happen. There are write up on how to install resistors or relays here and there to help save the switches but it seem you can have other issues.

I am not a tech person but it seems the easy fix is to replace the blower fan before problem get worse than just fixing a switch. Even with limited ability you can change a fan blower in about 30 minutes. If you are having switch issues, fan working on certain speeds but not others (bad switch) or blowing in high only (bad resistor) this may be only the beginning of a never ending problem until you replace the blower motor (even though it seems to be running fine).