Hope someone can help me with a vaccuum problem. From inside the vehicle, when I call for heat nothing happens. I replaced the heater control valve today and still no heat. Could the control valve inside the vehicle be the culprit? All the other vaccum operated divises seem to fuction ok The windshield defroster door, floor door, ect. it deflexs the air where I want it, but there is no change when I use the heater control knob inside. Any suggestions and could someone post a copy of how thw vaccuum line run. Thanks a million.