My 68 Skylark has no heat at all . Recently went through HVAC system after dashboard resto and addressed the following. Removed , cleaned control unit ( original A/C car ) , all vacuum lines inspected and changed where needed , blower switch-wiring- resistor plug changed . All 4 blower speeds work and likewise all the ductwork/hoses was gone through and replaced as needed . Heater core was back flushed ( very dirty now clean ) . New heat/ defrost cables from Old Air were installed with limited success. Heat cable was straightforward but blue defrost cable is too long making it impossible to connect to defrost door . The defrost and heater doors do move freely when manually opened. The vacuum switch on the fan speed switch was also changed. Car was purchased a few hrs ago but the wiring/ vacuum lines were a mess . Because of this the HVAC system never worked . Heater control valve was leaking and changed when purchased. Currently with heat door wide open in heat position I have no heat . The incoming heater hose is decently “ warm “ the return is cold . Radiator is full with new 160 thermostat. Thought I went though everything but I’m missing something. As always any and all opinions welcomed.