bad motor or capacitor
Does the blower run? Runs only on high?
Something is still wrong with it, and without seeing it no one can yell you what it is.
It is possible that the circuit breaker for the compressor unit is thrown (switched to "off"). Go outside to the compressor unit and follow the big cable up to the circuit breaker panel on the wall. If it is off, throw the switch to "on." If that is not the problem, something is probably wrong with the compressor unit. Turn off the breaker panel and call a repairman.
Loose connection?Bad fan motor (windings opening when they get hot)Loose fuse/relay?Bad or worn switch?Bad resistor?
That Goodman see nothing wrong in his conversations with the devil but is abhorred at anybody else doing so.
fuse, wiring, blower motor, blower motor switch, blower motor resistor
Generally, because something is wrong with it. Maybe a bearing went out, maybe the compressor is just worn, maybe it was damaged because of a refrigerant overcharge, compressor oil overcharge, or the wrong type of compressor oil used. Could be a number of reasons.
Most likely, it is a stuck contactor or relay that controls the compressor motor. If the compressor continues to run after the blower inside the house has shut off, the only way to stop it is to kill the power, either at a dedicated switch or sub-panel for the air conditioning, or at your main breaker panel. Turn off the power to the air conditioning and furnace system until you can have the unit serviced.
blower resistor is bad
The AC and heater are completely different subsystems. The heater relies on heat generated by the engine and circulated by the engine coolant (radiator fluid) while the AC uses a belt driven compressor and separate fluids. Their only normal commonalities are the blower motor (which you said works), the ducting and the control head.
If you have no blower speeds at all check the fuse, then check the blower motor switch and electrical plug for a melt down situation, then check the blower motor itself.
Check your blower motor relay!