Trying to turn on furnace for the first time. My arcoaire furnace upper motor only get hot but furnace will not turn on. If I put the fan on manually it works. Put fan on auto it goes off and upper motor become warm to the touch but nothing happens. No clicks no nothing

Brand and model of furnace ? Fuel type?

ArcoAire gas furnace approximately 1991 and yes I know it should be replaced

yes i know it should be replaced

Then replace it but check the reason it will not work in automatic before another one burns up.