The correct valve is installed and no changes. The blower motor functions properly, however, there's no change of the air flow, it only blows out the a/c vents and will not divert into HEAT or DEFROST mode. Diagnostic for a vacuum leak is in order and/or a faulty diaphragm on the box, or vacuum storage can under the battery tray ?? The FSM is very explicit regarding although I need to obtain a vacuum gauge to perform said test. Anyone recommend a particular brand / model? Thanks regarding. Tommy