My ac blows cold some days and then the next day it blows only hot

The air conditioning system could be experiencing one of two most likely failures. First, there could be an intermittent electrical concern with the system, allowing the compressor to turn on sometimes, but not others. This could be with a compressor coil, a relay, a cycle switch or another electrical component of the system under the hood. Second, there could be a climate control issue inside the vehicle. This could be with the temperature blend door actuator or controls that regulate temperature control. At times it could ask for warm air, and others cold. Hands on testing is needed to figure out what's going on. www.repairpal.com/repair-shops