Heater blows air into cabin and winshield defroster but is not warm. A/C works OK

Have checked flapper door, vacuum hoses, water hoses no leaks, radiator coolant full, water hoses get warm, cannot locate Heater Control Valve it is not readily seen under the hood. Vacuum gage checks OK on lines. On switching from A/C to Heat no sound can be hear. Please tell this OLD WWII China-Burma- sQUADRON commhowander, and BSCE what to do next-How do I DONATE-IF BY CREDDIT CARD WILL SEND NUMBERS OR PAY AN ON LINE BILL FROM BANK ACCOUNT