Ac blows cold then hot then cold

Hello, on the surface, it sounds like an electrical problem in the air conditioning system. The refrigerant seems to be there and intact -- but only active sometimes in the system, so perhaps it's electrically related. The compressor coil could be engaging only sometimes, or perhaps the cycle switch or high pressure cut off switch is an issue. I'd do some testing in those areas and go from there. www.repairpal.com/repair-shops