I have a honeywell chronotherm iii thermostat and the system is not on now. The display shows the time dash ac. Ac is in the right corner. The system swithc is on posistion on cool lowered temp but will still no run... any suggestions

More info. Does blower in furnace come on, does outside unit come on, or nothing at all happens? Check all breakers and disconnects at furnace and outside unit.