ive been trying to figure out exactly what is wrong with this furnace for a bit now. the blower is running constantly. even with the thermostat off. i tried changing that and it didnt work. tried a different board. no luck. then ive been testing and trying to jump out a limit to see if that will shut it off and that still didnt work. im sure it has to be a limit. the blower is running constantly and the burners arent coming on. it is a 1980's bryant 70%. here are a few pics i took to help. any help would be greatly appreciated. thanks.