Q: Heater blows cold air

The AC system needs to have a performance check run. The AC compressor needs to be checked for operation and a set of AC gauges put on the system to help diagnose the issue. If the system is low dye, it may need to be injected to locate a refrigerant leak. The AC system can generate pressures above 200 psi and can cause frostbite to exposed skin or even blindness if refrigerant is let out unintentionally. You may want to enlist the help of a mechanic, such as one from YourMechanic, who has the proper certifications and equipment to diagnose the AC refrigerant system. They will be able to verify what repairs are needed and can perform these services for you at your home or office.