The central AC is not working. There is no air coming out of the ducts nor does the compressor come on. I have already replaced the transformer/relay combination. Without the thermostat being turned to Cool, I can hear the transformer/relay humming when I switch on the 110V. I figure the compressor would come on even if the blower did not or vice versa. I also replaced the thermostat, one was handy. I would appreciate some pointers. If the blower motor is bad, would that prevent the compressor from coming on because of a biult-in safety feature ? I do not have a schematic diagram to see the flow.
Thanks.

I haven't see any 110/120 Volt Central Air units. Check both Breakers and both Disconnects for power(In and Out)
When thermostat is set to cool, their should be 24 volts to Compressor contactor Coil.