Squealing, grinding or grating – Noises typically occur when components needs lubrication or motor bearings have worn. You might need a replacement unit or simply have to have repairs made.
When warm air is blowing from your vents, it is often an indicator the system’s compressor has failed or needs service. It could be as simple as a bad capacitor or a blown fuse; five-minute fixes that won’t cost you much... or, you could be dealing with a refrigerant leak, which is a more costly repair.
WEAK AIR FLOW
This could be a filter problem or an issue with the duct work.
When there is leakage from or around an air conditioning there could be less serious problem that occurs when a drain tube is either blocked or broken or a more serious issue of a refrigerant leak, which could lead to costly repairs.
Could be a sign of a lack of maintenance, causing bacteria growth on your air conditioner coil. Musty smells can be a sign of mold either in the unit or the ductwork.