89 560 sel, would anybody have a diagram of the ductwork on this vehicle? compressor is running, r-12 is flowing, blower motor blowing, but only warm to hot comes out of the vents. Is the heater core and the evaporator on the same duct? or does the air get blown through different ducts for heat than a/c???? switches and vacuum valves seem to be working to put air out vents in dash or defog or floor....any ideas?