My a/c is no longer blowing cold air. The blower works and the heat works.

Hello, First step is to check the air conditioning lines under the hood. When running, one should be very cold to the touch. If this is the case, there is an issue with the A/C control unit (the part you use when operating the A/C or heater), a blend door in the HVAC box, or associated wiring. If the A/C has a leak, bad sensor, or lost the drive belt, it will not work at all. You will likely need to have the A/C serviced at some point during the repair, so you may want to let a professional technician handle the diagnostics and repair.