Why is my heater only blowing cold air

This could be a blend door issue or possibly a clogged heater core. Feel the 2 hoses to the core and make sure they are both hot when the engine is at operating temperature. If they are then it could be an airflow issue over the core caused by a blend door or motor. Some disassembly and inspection is needed. If you don't work on cars then use this link to find a good shop near you. https://repairpal.com/repair-shops Alex