HI, I have a 2.5 ton Ruud central unit (upstairs) which will not respond in any way to the thermostat: neither fan nor compressor-condensing unit will run or do anything. Unit is about 5 years old.
I have a Fluke meter and have accomplished some pretty serious auto repairs, but haven't much experience with central AC units. If someone could offer suggestions where to start looking, I might be able to find the problem.
I have checked the breakers and the outdoor disconnect for the condensing unit already.