If the relay is clicking but the compressor is not engaging, you may have a faulty compressor. Unfortunately, you'll need to pay for a service call to see if it's a problem with the relay or something much worse.
No, but your furnace still does
the filter on a central unit is the same as the furnace filter usually located in duct work directly beside furnace
it's the same as the furnace filter. the air conditioner runs through the furnace to push he cold air. change your furnace filter and you are changing the air filter on the air conditioner
yes.
The furnace or air handling unit in the house.
dead mouse inside the furnace
the big line is the suction for the the compressor in the A/C unit, The small line is the compressor discharge that goes to the furnace
Typically needs "A" coil atop furnace in ductwork, large vapor and small liquid copper lines running between a-coil and external (outside) condensor/compressor unit, 220 V at compressor end, and a professional to silver braze the commpr connections, evacuate the system, and install the refrigerant.The all you need is a thermostat.
With central air the furnace fan must be running to provide the air to the living space. If the furnace fan is not running then you get no air out of the ducts and the A-coil (the part of the ac system that is in your furnace duct) will freeze and shut down the compressor (the part that is outside).
Generally allow one day for replacing a furnace and one day for replacing an air conditioner. You need to replace furnace and air conditioner at the same time.
The compressor and condenser are usually located on the outside air portion of the air conditioner. The evaporator is located on the inside the house, sometimes as part of a furnace. That's the part that heats your house. The working fluid arrives at the compressor as a cool, low-pressure gas.
check to see if drain to unit outside in draining may be clogged